If you flashed to the official Verizon rom then just go to Adrynalyne's CF03 based roms:
http://www.samsung-omnia.org/adrynalyne%27s-kitchen/adrynalyne%27s-cf03-based-roms/Search would have lead you to the link above easily. Plus you can download a google maps .cab file, it doesn't have to be cooked into a rom for it to work. And if you're having trouble getting a GPS lock, consider where you live and your signal strength as a factor. It doesn't get more official than the CF03 rom so if GPS still isn't working, set windows to manager you location settings on google maps and make sure GPS location is turned on.