A BizSpark account will cost you $100 over the course of 3 years. You can get every OS they've released and run them on whatever you want. Yes, you'll have to spend time installing the OS, but Win 7 installs pretty quickly these days and that's the only way you're getting IE 9 anyway. It was a pretty good investment for us. I run Win 7 in VMWare Player on Linux & VMWare Fusion on Mac pretty regularly.
The admin interface sucks. Downloading software and getting your keys couldn't be much easier though. I haven't had to deal with the accounting end of it yet, so I can't speak to that.