Hi Jordan,
in general, unless you are planning to fit a massive battery bank, or huge bed, even the 2700 vans will carry enough for a camper conversion. That said, the bigger load rating you have, the more you have to play with.
Engine wise, the only engines available are the 2.2 in pre-facelift, or 2.0 post facelift. They do come in different tunes, from 100ps to 180ps. I’d suggest at least the 125ps
Hope it helps,
Ben