Getting a Mac Pro and some accessories, what should I be ready for?

[e3mac]

Hello everyone,
This is my first post here and obviously new thread. I have been reading posts around here for awhile. Gaining info and learning what works. Right now I currently have two older macs that have served me well but have been showing their age for years now. I have been planing to replace them with something more powerful and long-term. For more than a year I have been preparing (mostly financially) to get a Mac Pro.

The computer is going to be used for all of the basic needs like internet, video encoding, file hosting and maybe even games. However, the real use for the computer is going to be for design programs like Pro-E and Solidworks. I also am going to be running some FEA program too, probably mechanica (pro-e addon) or ALGOR. I have copies of both vista and windows 7 rc I am going to try running on it. Both through bootcamp and fusion.

I am ordering an 8-core 2.26 Ghz system with 8 GB (4x2) of ram a GT 120 and wifi just to have it. I also ordered 4 more GB (2x2) of ram from OWC to total 12 GB (6x2). I have a crucial m225 64GB SSD on its way (got it cheap) and another monitor.

I am really looking to find out what might not work or what issues, like AHCI drivers for windows, should I be ready for? I also don't know if that graphics card will be enough. Any questions or advice is greatly appreciated. Especially with how to configure it. I also look forward to finally having a user name so when I see an issue I know something about, I can finally say something and help.