motherboard needed for HTPC & gaming

Hi all,
This is my first post so be kind lol. I have been an avid reader of Tom's for a good few years.
A bit of background:

I am about to build a HTPC for linking upto a Pannasonic plasma via an arcam AVR300 amp.
The HTPC will be used for TV watching and recording. Storing all my music and films. Playing high deffinition media (from disc & hard drive). Browsing the internet from the settee. Last but by no means least PC GAMING!!!

Now i know that a lot of people build these HTPC's to be quiet and cool so there is a compromise there.

I will be using dedicated cards for both video and audio etc. (No onboard stuff here)

I will be using upto 5 hard drives. 1 for the OS and the rest in raid for storage/backup.

CPU wise I dont really mind AMD or INTEL ( the last pc I built for home is a dula Athlon MP system and it is still running strong today)

I would like to stick to Nvidea for my Gfx card so a motherboard with Sli rather than Xfire would be my choice. I wont rule out Xfire if it is a lot better board on this occasion?

I will also be using media portal etc as a front end.

I was thinking of using an 8800GT for the Gfx card and I noticed a lot of these are PCIe2, so maybe that might be a feature to consider.

The reason that I am asking on here about motherboards is that the choice is immense now and it is driving me mad.

Any help on choosing a good board for this application, that will also be reliable. Then FANTASTIC

I look forward to any help here.

Kev

For example, I am also configuring my new HTPC, based on Intel platform, and first thing that I choose was case. I choosed Thermaltake LANBOX Lite VF6000BNS, which supports only mATX MBOs. Next thing that I found out, is the best (fastest, with the most capabilities: SATA,RAID,firewire...) motherboard: Gigabyte GA-G33M-DS2R. Maybe someone knows for better choice? And most important thing, besides that above case looks very pretty (ideal for HTPC), and is not so expensive, it supports two graphic cards in SLI mode, or one 8800GTS card.