You sure CANNOT use the same rom thats built for the i780 and flash direcltly! The drivers, OEM folders (critical files/apps/dlls), boot section and the XIP section will be different on your epix. However, the process of cooking an epix rom will be exactly similar. You can follow my blog to get pointers on how to do this. the only difference is, you start with a working epix rom to disassemble, customize and repack!
cheers