Okay, what all roms have you tried?
Just the stockoptv?
Try installing Aphrodite 1.3.3, and use the activate app on that. (I haven't checked Harmonia's app to see if it works, but it should). I have flashed S roms before and was usually able to get the 3g running again by using a different rom and using the activate app, however some roms the activate app doesn't work. The Stockoptv rom, I haven't tried that version, but I have used similar and never could get them to work properly. I'm not sure why, they just didn't. If the activate app doesn't finish, re-run it, it once took 3 times for it to work for me.
Before flashing the other roms, in recovery, select wipe/data and then go into advanced and wipe dalvik cache as well. Don't use anything like Romtools for this. This way you have a better chance of clearing out the old files. This will wipe out your phone though. It doesn't sound like you are getting a good wipe before you flash.
If that fails, maybe someone can install a stock nandroid, wipe, then pull another nandroid to upload to you. I'm not sure how much info the nandroid will retain is the issue, but I certainly wouldn't say your phone is dead and done. I've done the same thing as you have, and recovered it.
When you do get it back, NANDROID!
Always, before you install a rom. Any rom for that matter. Doesn't matter if you are wiping or not.
I always pull a nandroid and then use MybackupPro (my preferred system) or Titanium Backup for a second backup. This way I can restore data, apps, or the entire system. Sorry, about keep mentioning the nandroid, I didn't mean to rub it in or chastize, it happens when you respond to lots of threads. However it IS important to do it. A lot of people's phones would be fine had they done it.