Sprint activation, need stock ROM for rooted phone.

I managed to get a HTC EVO 4G, working after its ROM was deleted. Its now running Cyanogenmod 7.2 . It was already rooted, running Supersonic EVT2-2 and HBOOT version 0.79.0000, plus some other info I can provide if needed, April 14, 2010 is the date listed. RA supersonic v. 2.3 is listed in android recovery mode, or it was rather after using ROM manager app, ClockworkMod recovery is now listed when entering recovery mode from the bootloader.

My problem is activating this phone for new service with Sprint. As far as I know, not possible running the current ROM Cyanogenmod v 7.2 ( CM 7.2).

I need to restore to the stock ROM, however finding a stock ROM for the phone, that will work with it's current setup (rooted) has not been easy.

So if anyone knows further details on this, let me know? Need a stock ROM that will work .

I have looked extensively via searching and reading on xda dev site and others, i am still not clear on a safe way to do this. Safe = a non bricking or removing or changing the current bootloader etc.

I have backed up the phone's current install.

I wish to activate it soon, since its a time sensitive issue. Once i have the correct stock ROM for my current setup (rooted) , flashing for activation and back to my current ROM is fairly easy.

I didn't want to make this question too long, listing a ton of tech. info.

Any input would be welcome of course.