SUPERMICRO X7DAL-E for new build

I have always like Dual Intel CPU's, the first one being the PC-DL (1st OC - 1.6ghz OC'd to 2.4ghz on air w/minior mods) (2nd 2.4ghz OC'd to 3.2ghz on air).
The current MB is a i7505 S2665 Tyan w/stock 3.06ghz chips and now want to build a sometime "gamer", video editing, rendering....

Anyone familiar with Supermicro?? Are these good MB's? OC'able? Very first PC was an AMD Opteron that I modded to run, back then at 1.03ghz and comming back to AMD, all these numbers, Duo, Quad core are all Geek to me.

Newegg.com - SUPERMICRO MBD-X7DAL-E-O Dual LGA 771 Intel 5000X ATX Server Motherboard - Server Motherboards

The list so far:
1. SUPERMICRO MBD-X7DAL-E-O Dual LGA 771 Intel 5000X ATX Server Motherboard - Retail
2. Intel Xeon E5410 Harpertown 2.33GHz 12MB L2 Cache LGA 771 80W Quad-Core Processor - Retail (hopping for a good OC)
3.Kingston 4GB(2 x 2GB) 240-Pin DDR2 FB-DIMM ECC Fully Buffered DDR2 533 (PC2 4200) Dual Channel Kit Server Memory
4. SLI's, EVGA 256-P2-N758-TR GeForce 8600GT SCC 256MB 128-bit GDDR3 PCI Express x16 SLI - (will get one for now and the second later on.)
Have a Stacker case with dual EPS PS's, so it's just switching out the old MB and installing the new one.

Should I stay with XP Pro or go with Vista Home?

Budget around $8-900 if that is reasonable.

Please add or subtract with your recommendations.