mollie, don't let livebearers freak you out. if you don't want to deal with babies or worry about rehousing them, either get all females or simply don't worry about the babies when born, just let nature take its course (the adults will mostly likely eat all the babies before you ever even known she's given birth). sounds a little cruel but its perfectly natural and okay. mollies are great fish, so are platys and guppies. yes, they can be hardy (though in my newbie experience, guppys do NOT survive new tank syndrome, so please follow alien annas post and do a fishless cycle, will save you and family the heartache of dead fish and wasted money, will save the fish a lot of uneccessary pain...............)
what size tank did you end up getting?