So, let me get this straight.... you're buying a Mac to run Windows, but then you'll run the actual OS (what makes a Mac, a Mac) on top of Windows in virtualization?
Seems like a lot of trouble to go to for absolutely no benefit.
Yes, I'd recommend VMWare Workstation on Windows, although you could try VMWare Player (free).
Sure - you could wipe the hard drive clean, pop the Windows disc in and have at it. It will behave like any other PC at that point. But again, why would you do this? Just because something is possible, doesn't mean it's practical.
It'd be like buying a Ferrari, ripping out the engine and popping in a 4-cylinder, just because you're more familiar with working on less exotic engines.
Possible, yes. Practical or advisable? No. If you like Windows, it suits your needs and the only use you would have for a Mac is to use it as a plaything, then here's what I would do.... buy a decent Windows box (it will likely cost you about 1/4 what you would pay for a Mac Pro). Take the money saved and get yourself a Mac Mini. Then, hook both machines up to a KVM switch, so you don't have to bother with two sets of keyboards and mice.
When you're done, you'll have gotten the exact same capabilities at half the cost and none of the hassle.