Two paladins should provide plenty of healing so long as you do your work and get your charms upgraded
First off if you want tier 6 and only run 3 you GOTTA have all UCs. As far as the pally/pally/bst not a bad idea, but the reason for 2 pallys is because you gotta have a off tank. Odds are with only 3 you won't touch t6 solo, well you could, but honestly i wish you the best of luck. Now if you plan on getting into a guild that would raid T6 and you wanta be able to hold your own, i'd go Sk/Pal/Brd. Your sk would hold good dps and act as a main tank cause it procs that nifty lifetap and the pally healing would help as well. The Bard would be your Ninjastrike dps/ Haste (and tempest line is awesome). I'd UC the SK first but get your pally a oracle 41 and bard a sorcer 41 first. Now this isn't the exact route you should go, but imo it's what i would try. Everyone says necro but only running 3 it wouldn't be worth the time in the long run, just push threw with the 3 you plan on ending with. Charms are gonna be your friend btw with only 3 so think about this wisely.