Best advice i can give is to use PPCkitchen and use 5060. Flash the official sprint rom (don't let it customize unless you're sprint) first though so you get the radio update.
Read the guide Nickle wrote i have in my sig. It's what convinced me to jump into my own flash.
http://forum.ppcgeeks.com/showthread.php?t=17667
That is also a good thread to read if you've not seen it.