www.matrixm.com is pretty good. i used to have a samsung a500 and got all of my ringtones from them. they are a pay site but they have thousands of free ringtones.

who is your provider? if it's sprint then go to www.ihateclaire.com and pay them 5 bucks and just upload midis straight to your phone. it's a one time 5 buck fee that lasts as long as you have the same phone #