You probably want the "lite" version. New vs used? depends on the used car? And if you want to build it. There is not much you need to do to upgrade the B5m lite out of the box. So buying used with upgrades might be a bit useless. Most of the crap people put on the car is exactly that....crap. New vs used? Do you need to save a couple dollars? Honesly with the coupon codes on tower/amain, buying used seems fruitless, unless you pick up a cherry used car for a steal.