I think this is an ok processor for gaming and stuff like that, other suggestions are appreciated, even AMD if you can give me a viable argument since its been a few years since I have followed the newest trends
First, I wouldn't get a miniITX case. That will severely hamper the search for a motherboard. To be honest, I wouldn't even be looking at miniATX cases either. Small form factors and gaming are pretty much mutually exclusive. If you wanted a smaller case for taking it to LAN parties, there are better choices than gettting a small form factor.
Second, I'd avoid that WD. The Samsung Spinpoint F3 1 TB is just as fast and a lot cheaper. I will point out that speed isn't really that important because you have a SSD in the build, though I'd consider dropping that out if the rest of this is too expensive.
Third, considering your budget, I'd also look at the i7-930. It's only slightly more powerful than the i5, but it's a little more future proof. Your budget should allow for this.
Finally, my additions:
Mobo: Asus P7P55D-E Pro for the i5 or Gigabyte GA-X58A-UD3R for the i7. Of course, that will require you to abandon the small form factor. The only mITX board I would even consider is the Ggiabyte GA-H55N-USB3, and that's really meant for the i3/i5 dual core CPUs. The reason it's the only one I'd consider is that every other one is from manufacturers that are known for poor quality and performance.
GPU: HD 5870 or HD 5970. You won't fit either of these in a small case though. If you absolutely have to stick to a smaller form factor, you'd likely be stuck with the HD 5670 or lower, which wouldn't game at 1920x1080.