New Comp Build Plan... seek feedback/criticism/suggestions

Hey guys! Working on piecing together a new computer to build at the end of the summer (Once i've earned up the money, ^_~). Going for several things here, in no particular order:
1) Upgradeablity - PCI-E and s939, etc
2) Overclockability - Good RAM, Processor, MoBo
3) Performance - Fairly high end (for my price range) components
4) Watercooling for looks, performance, and just the experiance of doing it.

So with no further ado, here's the lineup so far:
CASE: THERMALTAKE Armor Black Aluminum/Steel ATX Full Tower
PSU: Fortron Blue Storm 500w
MoBo: DFI LANPARTY nF4 SLI-DR Socket 939 NVIDIA nForce4 SLI
CPU: AMD Athlon 64 3500+ Venice 1GHz FSB 512KB L2 Cache Socket 939 Processor - OEM
RAM: OCZ EL Platinum Revision 2 1GB (2 x 512MB) 184-Pin DDR SDRAM Unbuffered DDR 400 (PC 3200)
GPU: eVGA 256-P2-N376-AX Geforce 6800GT 256MB 256-bit GDDR3 PCI-Express x16
-OR-
ATI 100-435500 Radeon X800XL 256MB 256-bit GDDR3 PCI-Express x16
HDD1: Seagate Barracuda 7200.7 ST380013AS 80GB 7200 RPM 8MB Cache Serial ATA150
HDD2: Seagate Barracuda 7200.8 ST3250823AS 250GB 7200 RPM 8M Cache Serial ATA150
DVDRW: LITE-ON SOHW-1673S Black IDE DVD Burner
CDRW: SONY Black IDE Combo Drive
Windows XP SP2
Regular ol' black FDD.

Watercooling Components (Dont have links right now, sorry)
Radiator: Black Ice Pro II
CPU Block: Swiftech MCW6002 (if I can ever find one in stock)
GPU Block: DangerDen Maze4 w/ acetal top, low profile
1/2" tubing
The new MCP650 Pump w/ no whine ^_~

Should be about it. I haven't yet decided on what kind of fans to get (120mm's obviously... need good CFM with a low noise. My current thermaltake sounds like a tornado in my case). Also could use suggestions for a fan controller.

Finally, need a little help deciding between the video cards. I currently have a 9800PRO which serves me fine, but I was thinking of SLI. Do SLI cards have to be the same type to work? And will it be widely used? Like I said, I'd like to have max upgradeability, but would also like to get the better components to start with... still unsure which would be better, an X800XL now, and switch to NVIDIA if sli becomes best, or start with the 6800GT?

Thanks for looking over it, any suggestions/critiques/etc are welcome ^_^

My Thoughts

Excellent overall choices.You wouldn't go wrong with what you have.
My Recommendations:
1) I like the ATI card also.However you are spending money for the SLI set-up
(MB) so I would recommend the 6800gt.I think a wiser choice than spending money on the ATI then taking a loss and selling it to go with the SLI later.
2) HD's- I would consider going with a HD with 16 meg cashe.Even though today newegg only has Maxtor hd's with these features by the end of summer other companies may have thiers availible.
3) For ease and flexibility if cost isn't a concern I would try to keep my HD's
in matched sets (both 250's ect) to keep open my raid options.
4) There is no need for the second drive to be a CDRW.Any DVD should do you.Keep your eyes open if the cost is only $29 thier is little additional cost but if you find a second DVD at a good price it should work for you.
5) As of now the Venice core you selected looks superior but by the time you buy check out the other cores and chips you may find a core you can oc better by then.

yeah ocz! i love ocz, they make such good ram. I will be getting the EL platinum revision 2 also along with the fortron blue storm. I cant wait but i dont have all of the money yet. Overall, they seem like good choices to me but i like Western digital raptors over seagate. They are much faster at 10k rpm. Anyways, good luck!