10 box machine setup, first timer help

[MiRai]

1. best CPU setup, which generation of i7, dual CPU even or higher core setups (more than 4), best option

The answer to this comes down to how pretty do you want each of your clients to look. The more cores you have available to you the higher you'll be able to turn up the video settings on the slaves; and keep in mind DX11 takes more horsepower than DX9.

A current generation Intel 4-core with hyper-threading should be able to make this happen just fine if you lower your settings on your slaves (I have no hard evidence to back this up), otherwise you're looking at a 3930K.

2. RAM setup, how much the speed of the ram matters and whether I'd go 16GB fast ram or 64GB slow ram or somewhere in between

Old, but still relevant:
http://www.anandtech.com/show/4503/s...he-best-ddr3/6

I personally wouldn't spend money on memory over 1866 unless it was cheap and had a CAS of maybe 10 or lower.

The benchmarks in this next article do not pertain to what you want, but the first page of it breaks down MHz, timing, and overall latency when looking at memory:
http://www.anandtech.com/show/6372/m...gp-with-gskill

3. GPU ideas, my understanding is one beefy one is better for boxing than 2 in SLI, if I understand things correctly with ISBoxer.

A top-tier single card with a single GPU will always get my vote. AMD currently offers cards with 3GB and nVidia currently offers cards with 4GB. If I really had to make a decision right now as to which manufacturer I'd choose based solely on hardware, I'd probably go with AMD.

While a few others have reported an increase in performance while using SLI (no idea how much), I personally don't see it (at least since I last tested it). I will test it out again in the future, but not anytime soon.

If you want the very most eye candy on your slaves, then you could always buy multiple GPUs and split the load between them; but that opens up a whole other can of worms...