I found the Pro RTM with a Volume Licensing key and it installed. No activation, of course.
But here's the thing, and my whole RTM experience in 10 minutes:
Installed system, setup wanted to restart the PC last time before setting up account. Okay, that's normal... The setup hanged just before restart and after 15 minutes of doing nothing I had to do a hard restart, after which I got served with a "error, you need to install 8 again" message.
Installed again, set up account, loaded desktop - went to change language preferences, at copy settings screen - BSOD
I actually had a dynamic Bing RSS theme from the Release Preview synced with my account, so it loaded an Aero theme lol
I switched to a local Windows account, no Aero on window borders, taskbar transparent with Aero lol
Went to change lang prefs again, copy settings screen freezes Explorer
Ran maintenance, went to check WEI - BSOD
Opened Action Center - froze
Opened People app - BSOD, then at next startup froze
Opened IE10, started loading TPLs - crash
xD
I pretty much gave up right then and there, not being sure if the ISO I found was legit (it certainly looked like it, I updated Defender and ran a full system scan which found nothing, so I assumed it wasn't a baddie) or was it just my computer bugging the hell out, because I know it has problems.
For now, I will have to go back to Vista. 7 doesn't work for me anymore because of the GPU issues, the 8 Release Preview I can't bother to download again (deleted ISO by accident and reformatted USB to install RTM), and in the future when I get myself a new PC (or perhaps the Surface) I will enjoy this OS