Gamers may prefer NVidia. Otherwise, I would suggest you to use ATi. My own Experience: a MacBook Pro (Core i7) with NVidia Graphics, running Windows and opening Adobe Photoshop CS 5 took forever to load rendering 3D editing. contrastly, a CPU with processor of Core2Duo 2.4 GHz, ATi Graphics (Radeon HD 5770) can perform the 3D modeling in Adobe Photoshop CS 5 Flawlessly.
It's just a suggestion after all. therefore, you are the one who will build the CPU and you're the one who decides!
Have a nice day and have a nice CPU!
BTW, I would suggest you to have more HDD. If speed matters a lot for you, then it's fine to use SSD. Otherwise, you may want a 1TB HDD (if you store movies, installing multimedia-related software, etc). Also, I think 16 GB of RAM is fairly enough. you can give the VM around 8GB to be shared for running 3~5 VMs at the same time, while you are using the rest 8GB of memory for your desktop: Gaming, multimedia editing, and others.
*My suggestions are referring to low cost, enough performance CPU.