if you're going for a first solo, i would reccommend a thief in there somewhere, as traps can be a real bugger. also a mage is neccesary in there to disarm mages (unless you take the inquisitor paladin kit).
so a mage/theif perhaps? or even a FMT (imho the easiest solo to do) to take advantage of the backstab. (mislead, every attack is a backstab
)
and the level ups for a solo triple class character are not that bad at all. my solo FMC really shot up in the level charts in chapter 2 and took out both kangaxx and the twisted rune with relative ease, without the use of major cheese.