rickss69, Welcome. I'm not the best to help you out, but I do know some things to get you started. I think you have the potential (in your specs) for about 45k points per day (Folding).
OS? Windows 7 64 bit. If you have experience with Linux, you may want to check this out:
http://en.fah-addict.net/news/news-0-176+cuda-dedicated-linux-distribution.php If this works, it would make no sense to use a VM, so I'm sure that if you wanted to be the trailblazer (sounds better than Guinea Pig), that your work would be much appreciated.
As for your CPU, find a stable overclock. (your specs calls this box Folding/BOINC build, but I'm going to assume you want to run Folding on it. It would make a good BOINC system (CPU) as well, but we sure could use another bigadv system for Folding) Folding will expose if your overclock is stable or not. Most seem to find their max overclock and then back off a bit. You'll want to run the bigadv units on a VM (Win7), and I have no experience with that so I'll let those who do help you with that.
As for those GTX280's, it does not matter if you sli them or not, just follow the instructions
here. That link is pretty old and recommends using the system tray client, which we do not recommend, but we do recommend the console client. The instructions work for the console client as well. You normally don't need dummy plugs (or DVI to VGA dongles) with 2 GPU's, but they are needed for 3+ GPU clients.
As for monitoring,
HFM.net seems to be the choice, especially with VM's.
Again, welcome. This from the guy who was hoping for some pie (top ten on the team) and you'll push me even further away.
j/k
Update: Emails from Fixstars state that YDEL is only available for purchase ($400/year) or to collage students with an e-mail address at a school.