How to get maximum power?

Hi! I'm planning on installing windows on my new iMac 11,3 i7 (with Mac OS X 10.6.4), mainly for two reasons:

1) I'm using Sony Vegas video-editing-software (Win only)
2) I'm obsessed with Microsoft Flight Simulator (Win only)

The most intelligent thing to do, to get maximum capacity from my firepower-stuffed computer, would probably be to run bootcamp. But since I need Mac OS and Windows simultaneously (video editing on win and adobe-series installed on mac) I'm going to need a cloud-system. So:

a) Can I get maximum capacity from my computer with windows even though running Parallells? (and how?)
b) Which windows-version would be most intelligent to install?
c) (Perhaps not the best place to ask this, but...) Should I go for Parallells or VMWare Fusion for this?

Thank's alot, brothers and sisters!