The 2600k was mainly for higher overclocking as from my read it can bench higher though yeah the 2500k is the perfect gaming CPU as you say. I did used to do some Maya 3D modelling and was learning to use Houdini and realflow for VFX but put it on hold as it killed my current system in render time.
I really do fancy 2 of those Hydro's as they are drop dead sexy and look gorgeous. Anywhere I can get guidance on setting up a dual loop as I really know nothing about water cooling. All I know is cocking it up will be expensive

But things like what parts, what size rad and hot to actually assemble two loops without a plumber!!
I've also seen quite a few high end builds using that 800D obsidian, is it really better than the Temjin? As Bit tech rates the TJ07 as THE best water cooling case?
RAM should be fine as it is rated v1.5 so good to go there just fancied slightly better CAS on it.
The blu ray costs about the same as the normal drives and I have a huge blu ray collection. I do hope Blue Ray doesn't die as I buy those for all new films due to my PS3 and the Bravia.
I had considered the 2 x Samsung as I intend to salvage one of those from my current system and wondered if Raid 0 would outperform a Velociraptor.
Soundcard is probably more to do with habit and the fact I always loved Creatives SB cards. Tbh if the on board sound from the Mainboard could match it I'd go for just that but alot of reviews do rate the X-Fi highly for games and the Xonar for straight audio.
Frankly for 2 x Hydro and a water loop I'm prepared for quite a few compromises as just the idea of the project gets me excited.