I would go with warrior, warrior, white, black.
I got fast to the finish last night using warrior, monk, white, black. The monk was taking huge amounts of damage in the final battle compared to the warrior. You get enough armor to equip 2 warriors to equal strength. Only drawback is only having one Excalibur. It would also be useful to have one knight casting the nul magics at the begging of the fight before he's tempered and hasted.
Nothing was really an obstacle besides the final boss. My characters were all level 33 when I battled chaos. So, level 7 magic was as high as I had. No special weapons besides Excalibur. Everything was collected from chests pretty much. I did grind levels a bit at the flying fortress as I was only level 22 when I got there.