Myself, I'd stay with the Intel Build.
Would recommend changing ram to CL7, if you can string for an extra 20/30 bucks - Don't think it buys a lot in terms of performance gain, but if you do a mild OC, it's woth it..
I have very simular build (Gigabyte UD4P) using Ripjaw 1600 Cl7 @ 1.6 V (Believe discontinued/replaced with CL6. They also had CL7 @1.65V which I bought to pair up with the 1.6 V and the 1.65 V runs fine at the 1.60 level (in it's profile it shows 1.60)
added - Didn't see in your build a 3rd party HSF (Stock intel HSF, while it works, it is at the bottem of the heap in effectiveness) would add another 30 bucks, BUT saves time and hassle if you later want to switch it out.
I realized the title is misleading. I won't exactly be using this JUST for gaming. Video editing, live streaming, broadcasting from a studio, and basically doing a LOT of things at once. I run a small studio that needs to handle high quality streaming.
I'll probably go with the GIGABYTE mobo. Is 6GB of RAM really necessary today?
As for the RAM, 4GB has kind of become a standard nowadays as many applications take advantage of the additional RAM and the reason to go with 6GB(3RAM sticks) is to take advantage of the i7 has Tri-Channel memory controller...