Bundle setup for oc'ing w/ i72600k and ~2000 Mhz RAM

Honestly, you don't need 2000 Mhz ram for Sandy Bridge, at least not if you are gonna be using it for anything other than highly specialized corporate applications (I think...don't hold me to that). There really isn't anything to be gained from buying ram faster than 1600, even 1333 Mhz. Take a look at the benchmarks here:
http://www.anandtech.com/show/4503/sandy-bridge-memory-...

Honestly, the fastest you will need is 1600, if even. Personally I would buy some decent 1333 or 1066Mhz ram and call it good, since there really is no notable difference between them in most cases. Don't forget, with Sandy Bridge you overclock using the multiplier, which will not change the clock speed of the RAM.
As for the motherboard, what kind of features are you looking for? USB 3 support? Integrated graphics? How many PCIE x16 slots? Etc...If you are on a budget, look in to the MSI P67A-C43. It has many overclocking features that are normally only found on boards that are close to twice the price, however it only has one slot for a graphics card, so there is no SLI/Crossfire. If you don't care about USB 3.0 and are only going to be using one graphics card, you should also consider the P67S-C43. It has all the same features as the other one, only it lacks USB 3.0 ports, however there is a connector on the board for if you buy a separate USB 3.0 card, and I believe with it you can still get the full transfer speeds. Both boards also have SATA 3. If you want a multi-card board, however, take a look into the Asus P8P67-Pro or the P8P67 Deluxe. Those are some of the most commonly used Sandy Bridge boards, however I have heard that they don't have the greatest voltage control, making overclocking more tedious, which is why I decided against them. You should also take a look on Newegg's motherboard section. From there you can select boards based on the individual features that they have, ie: socket type, number of graphics card slots, form-factor, brand, price, etc. Just make sure you also do plenty of review-reading  
Hope this helped!

Im using a sapph toxic HD 5970 4GB so no need for 2 gcards, i do want usb3.0 for future purchases. That and the ocing functionality are my only personal limitations really when u factor out the RAM. Just wondering how minor the difference would be between 1600 and 2000 mhz would be. Is it because of oc'ing limitations? It was mentioned to me that slightly higher speed on RAM may give some leeway to compensate for possible RAM speed loss when oc'ing the CPU (not fully versed on how the cycling etc and relationship between the two works tbh.)

Was recently looking at the asus p67 sabretooth as a possible mobo (due to local pricing) as well but i do not know how well it does with oc'ing. (as you probably guessed im now a little out of touch with it all). Any suggestions on more stable boards for oc'ing (since u mentioned voltage may be unstable on many sandy bridges).

Checking out the mobo section you mentioned. Thanks for the advice so far. \o.

Sandy Bridge systems have only five memory speeds available: 1066, 1333, 1600, 1866, and 2133. Nothing in between is supported, so don't bother getting any other speeds as they will be wasted. That 2000 RAM you mention will run at 1866.

On Sandy Bridge systems, CPU overclocking is done via multiplier. RAM speed is completely independent of that.

The price/performance sweet spot is 8GB (2x4GB) 1600 CL9 1.5v RAM. You can buy more expensive stuff if you want, but the small performance boost won't be worth the price (unless you find a killer deal like this: G.Skill 8GB (2x4GB) 1866 CL9 1.5v for $65 with promo code -- only until August 8th).

99% of the time, the performance difference between ram at 1333Mhz and 1866Mhz is a fraction of a percent. As is the case with gaming, different ram speeds will typically only result in a one frame-per-second performance difference, if even that. In some rare instances, it may be as high as 5 FPS difference, but considering the computer you are building, it won't be a noticeable difference. It would be better to stick to some 1600 mhz ram and use the extra cash to upgrade your CPU cooling or hard drives...or something. It's never a bad idea to put the money you save into something else.