I'm in the midst of upgrading my cpu/mobo/mem right now and I'm still pondering if I should stick to the original plan of a 965 BE on ASRock 970 EXTREME4 AM3+ with my already puchased G.SKILL Sniper 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800), or go the extra mile and have the extra horsepower of the sandy bridge on the 2600k or 2500k. Primary uses are Folding@home(almost 24/7), Gaming(have a 6850), 3D modelling with blender. My current specs really really aren't cutting it, AMD x3 8400 OC to 2.3 24/7(This is sub 2008 era chip), an old ECS AM2+ mATX mobo with 3gb DDR2 600 mem all topped on Win7 Ult 32bit. CPU is really bottleknecking all of my gaming, Esp BF3.
If you canSee to give me insight on wether I should go SB or not it would help out alot, if you do think I really need it please feel free to recommend a Mobo that is either for the 965 or SB that IS ATX(will not stand for this mATX BS anymore lol), will have CF for future GPU upgrades, and be able to support my already bought Gskill Sniper 1600(I know that pretty much everything is these days with this mem).
In the near future I also plan on taking on an SSD preferably one that does SATA III, and a new PSU of about 850W instead of me 500W currently.
However your current choice is solid. The BE can be overclocked well enough just get some good aftermarket cooler and really start pushing it to its limits. You said you were going to do some rendering / modeling so you may want to add more ram but I think you did your homework and choose wisely with your setup. Great budget, can be over clocked and room for upgrade if you feel you need it.
Intel chips and boards are nice, but the cost is through the roof. Since AMD dropped the ball with the FX chips stick with the 9xx-1xxx BE series chips. For the price of a Intel chip you can get a AMD chip + supported board.
I recommend getting a small 60 GB SSD drive for Windows installation only. The boot / shutdown speed is lightning fast! You will not regret it. Keep your current mechanical HD for storage and all other installations. You've saved money by not going Intel it's the least you can do for yourself
My only bargaining through going with the Intel platform is that you get the performance and future-proofing of having the raw power but I guess you do have to pay the price for it haha, also, I was thinking about getting a 120gb SSD as the price is getting down to the point of $1/gb and it'd be nice to have some headroom for basic apps like Chrome, CoreTemp, basically any rudimentary things I'd use a few times daily. Also should make a note to ACTUALLY purchase Windows this next while too lol I'm running Win7 Ult 32 bit Pirate edition =P
Also you mentioned coolers, I was thinking about going the Corsair way around it and getting either the H80 or H70(to get my own fans, am going to get two UV Blue Gelod wings for my side panel with a UV Cathode or possibly green if I want to change my whole colour scheme but I already have a blue xigmatek and blue CM.) Definitely NOT going air, I want something newer age and colder, and unless I want to make as custom loop I'd need to put the Rad on the outside of my case as I only support a top 140, rear 120, and two side 120's.(Forget about the front, that's untouchable) I'd have to get a prebuilt loop.
Gross CA tax I forgot Sounds like you have it all planned out and already thought about space for water cooling the cpu.
I'm still running pirate copy - I will invest in windows 8 whenever it comes out I have a 60gb SSD and with windows installed, updates, and all the hardware drivers etc.. and still have 28gb of free space.