Parallels Desktop - 6 will run Windows 7 perhaps better than your PC - however, you have to buy both Parallels and Windows 7... And 7 is a hog...
But, you should notice no difference - and you can still run MacOS (I assume Lion, but it should work with any 10 based OS) at the same time - even games - like Call of Duty run pretty good - sort of depends on the video card you are running...
Ohhhhhhhh - you have WartHog... I am impressed, I was told WartHog wasn't even out in beta form yet... wanna share 