Have you gotten you phone to boot yet? Or is it still stuck between the White HTC screen and Black screen?
Before that recap for me exactly what you have flashed. I know you flashed the GB Rom and then had no signal because you needed to flash the GB radio. Which radio did you flash and how did you do it. And once you did that has it ever booted correctly or have you been stuck since.
Sorry to ask so many questions, but I want to get a good idea on where you are before I give you instructions to try to help get you fixed up.