Surface Pro series are all full Windows 8.
Surface RT (name for the first gen Surface RT tablets) and Surface 2 are both RT powered, ARM based, therefore they run none of the standard desktop Windows apps.
You can literally only load special RT software on them via the Windows Store. They are not worthy of even being paperweights, IMO. They will not run x86 code/programs.
That being said, the RT powered ones do come with Office, lol.
Honestly, the Surface Pro 2 in 64GB form is about $400 more than it should be, starting at $899 and going up to $1799 for the 512 GB SSD one. I'd just buy a decent laptop. Better battery life, better connectivity (like an Ethernet port), most usability.
There are, of course - many other manufacturers making cheaper and more powerful full Windows 8 tablets.
On the 64 GB Pro 2 models, there's only 47 GB free drive space free out of that 64 GB drive.