Ringtones for Phones

I have T-Mobile, and I’m not too fond of the phone options I have. I’d switch to another carrier, but I’m on a family plan that’ll cost $200 per-number to cancel, and there are 4 of us on it.

I’d like to buy a phone unlocked online but I’m not sure where I could find the best deal and where I’d be least likely to get ripped off. I don’t really trust eBay for phones.

Anybody know a good, trustworthy site to buy unlocked phones?

Thanks