I have a program called ringtone media studio. it gives me the option to create ringtones wallpapers or use one of the ones the program is included with. The program also has an online library you can download from. You can download a trial version from www.bvrp.com if you decide to purchase the program you can use the promo code I used to get a 15% promo code tech68.
Another good program is Xingtone it will send the tone to your phone via txt msg, but you'll be charged for data transfer...which can get semi expensive. Here's a place for you to dl factory ringtones to your comp. http://vzw.ztango.com/vzwtones You click on the purple smiley next to the tone u want...windows med player will start playing the file > you select > file > save as in windows med player and u save the file to your phone...then transfer via data cable.
