You can rent time on a longarm at Quilt Country. That might help your decision. Urban Spools in Dallas also rents time, but I have no idea what machines they have. (They've changed owners, but they would not let you rent time on the computerized one with the old owner.
It might be worth it to actually quilt a quilt on a machine to see how it works for you. (I don't have a longarm, nor have I rented time, but I believe I would do it, as it's not really a sales situation.)
bkay