Classics or KSos. These are the most minimalist and basic. I prefer classics because they're quicker to get on.
I'd have to agree with Hawkeye. Although I don't lift weights myself, I have a lot of friends who do. The few people I know seem to love the original soles (Classic, KSO, Sprints) for lifting weights. This isn't saying that the others won't work just as well, though. Justin just did a review of the Komodo's in which he seemed to love them for lifting. Good luck choosing, and welcome!
Check out the KomodoSport review herehttp://birthdayshoes.com/vibram-fivefingers-komodo-sport-review