Well I researched mine before purchasing it... I did a research because I was impressed with i7-3960X but costs like $1300.00 bucks so I purchased a i7-3820 also and purchased a RIVE... But basically I just researched informations that's related to compatibility to a LGA 2011 MOBO...
For my build I chose a 2400mhz 8GB DDR3 Kingston because I'm on a budget and figured I'd purchase main componants then later on I can upgrade my Build.
I'm not sure what kind you wanted to build but if it's for extreme performance I'd suggests to purchase 2400mhz DDR3 for examples at a lower mem... after all I purchased mine because I wanted to O.C. it later on once I've got a decent cooling system going on to cool down the O.C. PC componants... after all the main enemy for a O.C. Mobo is heat... since heat damages hardwares...
I'm also a novice builder so I'm not knowledgable in building since my RIVE is also my first self-custom build... My first ASUS performance PC was purchased in ibuypower.com
So I basically studied my old PC P5N-D then do a research the requirements for Rampage IV Extreme. Basically just follow the requirements and it even shows the hardware on the websites that's compatible to RIVE... like I purchased a Phantek heatsink.
And I had to purchase other things that I never thought I would require... like heatsinks and extra fans... since I'm not familiar with liquid cooling... Cos I'm a cautious person when it comes to anything liquid... I don't want to have accidents or leakage... Since water conducts electricity and all... LOL...
At first I was thinking of Corsair H-80 ot H-100 what it suggested but instead I wanted to learn how to O.C. it since I was limited to my P5N-D cos my PSU broke and had to be replaced so a local bestbuy supergeek told me I don't need a high PSU.. which they replaced it with 750watts But then I couldn't overclock my P5N-D with 750watts Corsair... Everytime I O.C.'d it at 20% it keeps restarting and shutting down multiple times... And I recall supergeek technicians said we never seen a PC like NZXT before... I was like "oh.. oooo... I'm in trouble..." Cos I'd expected supergeek to know these things... but I was surprised that in my local area they don't seem to know these custom PCs just a regular office build PCs...
So just basically do what I did... just research the hardwares that's related to the Rampage IV Extreme which is in the website... Like if it has PCIxE and how many SLI's and the spec requirements for other hardware componants...
I guess it was sort off 99% successful for me for a first time custom build myself since I was able to make Win 7 64-bit working... I'm just having problems with my EVGA 560Ti incompatibility... heh heh... At least I can say I don't have a degree unlike my local PC technician supergeek... they don't know the type of MOBO's that can O.C.'s requirement extra wattage helps instead of limited watts that cannot overclock...
And I heard main concerns of 32GB DDR3 is stability... Most softwares required 2GB SDRAM but I dunno why people would want more than 16GB cos I heard about Skyrims that they're still having updates to hold up to 12GB to 16GB of SDRAMs... and I heard they don't support 32GB SDRAMs yet...
ASUS Entheustic <3r MOBO RIG: First RIG first custom built myself...
Antec Darkfleet-80 (Antec said it's a new Full Tower ATX.. and also said copied from other ATX..) / Rampage 4 Extreme / Intel i7-3820 (hope to upgrade to i7-3960X but cannot afford on budget atm...) / EVGA 560 Ti OC 256-bit 1GB 4-way SLI Kingston XMP 8 GB 2400 mhz DDR3 / Cool Masters 1000w PSU / Phantek European design Heatsink for LGA 2011 /ASUS Blu-ray Drive / Seagate SSHD 500GB Momentus XT Win 7 64-bit Ultimate / AutoCad2000