I'll try my best to answer the question, but if I ever decide to do another run with that party, I'll need a lot of additional planning and testing. So treat this as a first guess on a good route for Fi/Rm/Rm/Rm.
First, this party is pretty interesting in itself but it lacks the Fighter duo that allows first-trip Eye farming, and it lacks the White Mage who allows early Geist hunting. This means that there is probably a better battle offset than 117 for this party, but I don't know what it is yet. For this reason, I won't go into details about the exact battles that are used for earning Level 5 before the Marsh Cave. Let's just say we aim for maximum Ogres, Sharks, and Kyzokus, and we run from the rest.
1. Buy 4xRapier, 2xChain, FIRE, LIT, go fight Garland, and if possible fight a Ghoul.
2. Back to Coneria, Inn and buy LIT and CURE.
3. Travel to Pravoka, fight 2 Ogres, then go fight Bikke. Buy 2xICE and Inn.
4. Sail to the Dwarf Cave, but go in Coneria on the way and buy 2xChain, 2xCURE, FIRE, FOG, and 2xTent.
5. Pick up the 1025 G in Dwarf Cave, then travel to Elfland.
6. At Elfland, buy an Iron shield, a Wooden helmet, 12-15 Heal potions and 7-10 Pure potions.
7. Tentx2 in front of the Marsh Cave, pick up Short sword, Copper bracelet, Iron armor, a House, and the CROWN.
8. Go straight to Astos, House in front
9. Do the side quests for the KEY. While at Elfcastle, pick up the chests, and in Elfland buy LIT2, 3xFIR2 and 2-4 Soft.
10. Do the side quests toward Melmond. Buy some Heal and Pure potions at Coneria on the way.
11. Buy Long sword and Iron gauntlet, then go to the Earth Cave. Cabin in front. Should be Level 6.
12. Go to the Vampire, pick up Coral sword on the way, then go directly get the ROD and back, re-House. Level 7.
13. Do the Earth Cave and defeat Lich.
14. Go to Crescentlake, sell fruity swords, buy Silver stuff, get Canoe.
15. Do the Ice Cave, then buy goodies (FAST, ICE2, CUR2, maybe AFIR/MUTE for Ordeals)
16. Do Ordeals, pick up Zeus, Heal, etc. Class change. Should be around Level 10-11.
17. Do the Gurgu Volcano. Pick up the second Ice sword. Kill off two Red Mages. Farm Agamas until Level 16.
18. Revive all. Buy WARP, LIFE and CUR3. Buy 2xRUSE and potions. Buy BOTTLE. Buy 3-4 x ProRing and get OXYALE.
19. Do the Waterfall, get chests and CUBE, WARP.
20. House, do the Sea Shrine top floors, WARPx2, do the lower floors and Kraken. Don't get Opal armor and shield.
21. Learn Lefeinish, WARP. Get CHIME at Lefein, WARP. House in front of the Mirage tower.
22. Do the Mirage tower and Sky palace. Pick up good chests. Avoid Warmech. Defeat Tiamat w/o BANE.
23. Pick up Xcalber, restock on Heal potions if low, then House in front of ToF.
24. Enter the ToFR. On Earth floor, petrify all but the Knight. Beat Lich2, then Kary2.
25. On water floor, unpetrify one weak RW. Beat Kraken2.
26. Pick up Masmune, then unpetrify the strong RW, WARP, and defeat Tiamat2.
27. Revive whoever's dead (one max.), swap Ribbon toward Knight, defeat Chaos.
Essentially, do Ice Cave first and farm Agamas, plus vary strategies against bosses.
First, this party is pretty interesting in itself but it lacks the Fighter duo that allows first-trip Eye farming, and it lacks the White Mage who allows early Geist hunting. This means that there is probably a better battle offset than 117 for this party, but I don't know what it is yet. For this reason, I won't go into details about the exact battles that are used for earning Level 5 before the Marsh Cave. Let's just say we aim for maximum Ogres, Sharks, and Kyzokus, and we run from the rest.
1. Buy 4xRapier, 2xChain, FIRE, LIT, go fight Garland, and if possible fight a Ghoul.
2. Back to Coneria, Inn and buy LIT and CURE.
3. Travel to Pravoka, fight 2 Ogres, then go fight Bikke. Buy 2xICE and Inn.
4. Sail to the Dwarf Cave, but go in Coneria on the way and buy 2xChain, 2xCURE, FIRE, FOG, and 2xTent.
5. Pick up the 1025 G in Dwarf Cave, then travel to Elfland.
6. At Elfland, buy an Iron shield, a Wooden helmet, 12-15 Heal potions and 7-10 Pure potions.
7. Tentx2 in front of the Marsh Cave, pick up Short sword, Copper bracelet, Iron armor, a House, and the CROWN.
8. Go straight to Astos, House in front
9. Do the side quests for the KEY. While at Elfcastle, pick up the chests, and in Elfland buy LIT2, 3xFIR2 and 2-4 Soft.
10. Do the side quests toward Melmond. Buy some Heal and Pure potions at Coneria on the way.
11. Buy Long sword and Iron gauntlet, then go to the Earth Cave. Cabin in front. Should be Level 6.
12. Go to the Vampire, pick up Coral sword on the way, then go directly get the ROD and back, re-House. Level 7.
13. Do the Earth Cave and defeat Lich.
14. Go to Crescentlake, sell fruity swords, buy Silver stuff, get Canoe.
15. Do the Ice Cave, then buy goodies (FAST, ICE2, CUR2, maybe AFIR/MUTE for Ordeals)
16. Do Ordeals, pick up Zeus, Heal, etc. Class change. Should be around Level 10-11.
17. Do the Gurgu Volcano. Pick up the second Ice sword. Kill off two Red Mages. Farm Agamas until Level 16.
18. Revive all. Buy WARP, LIFE and CUR3. Buy 2xRUSE and potions. Buy BOTTLE. Buy 3-4 x ProRing and get OXYALE.
19. Do the Waterfall, get chests and CUBE, WARP.
20. House, do the Sea Shrine top floors, WARPx2, do the lower floors and Kraken. Don't get Opal armor and shield.
21. Learn Lefeinish, WARP. Get CHIME at Lefein, WARP. House in front of the Mirage tower.
22. Do the Mirage tower and Sky palace. Pick up good chests. Avoid Warmech. Defeat Tiamat w/o BANE.
23. Pick up Xcalber, restock on Heal potions if low, then House in front of ToF.
24. Enter the ToFR. On Earth floor, petrify all but the Knight. Beat Lich2, then Kary2.
25. On water floor, unpetrify one weak RW. Beat Kraken2.
26. Pick up Masmune, then unpetrify the strong RW, WARP, and defeat Tiamat2.
27. Revive whoever's dead (one max.), swap Ribbon toward Knight, defeat Chaos.
Essentially, do Ice Cave first and farm Agamas, plus vary strategies against bosses.