Mobo: Rampage Formula, P5E Deluxe, DS4?

Alright, the rest of my system:

Intel E8400 CPU
x1 Visiontek 4870 GPU (adding another later)
Corsair XMS2 4GB DDR2 800 RAM
WD6400AAKS 640GB
x1 Western Digital 640GB Storage
Cooler Master RC-690 Case
Corsair 750w PSU
XIGMATEK HDT-S1283 Heatsink + Retention Bracket
x6 Scythe S-FLEX SFF21F 120mm Fans
Samsung Black 20X DVD+R 8X DVD+RW SATA

With this setup, which mobo should I get?

I was originally set on the ASUS Rampage Formula http://www.newegg.com/Product/Product.aspx?Item=N82E168... but I really don't think it's worth $300 if I'm not planning to OC too much (I'm only going to OC the CPU to ~3.6 gHz but if I go higher I'll OC the RAM too).

So I've looked at two cheaper options:
ASUS P5E Deluxe
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
GIGABYTE GA-X48-DS4
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Out of the three, which one would be the easiest to set up and OC? Will the rest of my system fit into all three mobos?

Which has better (easier) BIOS and support, Asus or Gigabyte?

Summary: Which board (Rampage, P5E, DS4) has the best price-performance ratio, easiest setup (BIOS) and OCing (but not hardcore), and best reliability/customer support? Also, will all comfortably support the Xigmatek S1283, Corsair XMS2, and Crossfired 4870s?

Oh, I also want the best onboard soundcard.   Thanks!