Which chipset? Which motherboard?

Hello,

I'm going to build a new PC, which should replace my old PIV 2.4.

The CPU will be E4300 - having in mind to overclock it, of course

I won't use my new PC to play games (although I could from time to time) - I need it mainly for work, since I am a developer.

My optimal display configuration is made up of a 24" lcd monitor with a res of 1920x1200, plus 2 "satellite" 20" LCD with a res of 1600x1200.

So, I need to build my new PC with 3 DVI connectors - I think that the obvious choice is using 2 graphic cards - either nvidia or ati, no specific preference.

Other constraint are:
- availability of RAID 5 controller
- at least 2 PCI slots
- at least 2 PCI-E x1 slots
- SPDIF out

I've restricted the list of chipsets to the following 4:
- P965
- i975
- 680i
- 650i

Each chipset has his pro and cons, and I'm not sure what I have to choose:

i680:
PRO
- good for OC
- 2 PCIx16
- excellent feature set
CONS
- price too high
- poor RAID performances

i650:
PRO
- good price
- good feature set
- 2 PCIx16 (even if working at x8 using 2 cards)
CONS
- poor RAID performances

975x:
PRO
- good for OC
- good RAID performances
- 2 PCIx16 (working at x8 with 2 cards)
CONS
- no recent models available
- prices quite high

965:
PRO
- good for OC
- excellent RAID performances
- reasonable prices
CONS
- when using 2 graphic cards, the 2nd one works at 4x
- (not sure about this) when a 2nd card is used, PCI-E x1 slots are disabled

My preference would be P965, but the dual graphic card issue could be a problem.
Any suggestion?

Thanks
Antonio