Tdean,
I strongly suggest sticking to Intel/Intel combination motherboards for any sort of professional use. The only non-intel chipsets I recommend for Intel CPUs are ServerWorks. Get it? SiS is alternative garbage meant to sell ad space and VIA isn't a whole lot better. I deploy mid-line servers and build clones on the side, and to be honest I look at even the fastest clones as not much more than toys compared to lets say a multi processor Dell PowerEdge 2500. Still, one of those puppies decked out for bear will run you about $3000 with PERC3 and RAM. You can of course build a nice 'home brew' file server for about 1/3 that will suit the need nicely, if you buy solid components. That's the key.
If you're going to go alternative then look into a Athlon/AMD combination. Personally I think the P4 is a paper tiger compared to the better Athlon/AMD based motherboards, but.....Intel is a standard and many IT managers still cringe when they think of running production services off an AMD chip. To bad really since the better Athlon/AMD boards are as good as anything made by Intel in my experience. Midline Intel based servers however are in a different zip code than AMD.
So, stick to P4/Intel chipsets if you go that route. If you go non-Intel go Athlon/AMD. Nuff said....
OK, let me give the lecture about RAID controllers. Promise and the rest of the ilk need to be sued for false advertising because they are not true RAID cards, and Tom needs to stop endorsing this crap and being a hypocrite. They are nothing more than cheap, EIDE controllers with some logic built in to do channel mirroring, etc. They are no better performance wise than integrated graphics and have the same limits and marketing lies. They basically gang-bang your CPU and cause a serious peformance bottleneck when it comes to any time of network/file services on Windows based systems.
This is why SCSI is the standard on production servers and you rarely find an EIDE controller or AGP slot in a main-line server. Who needs that f^^^^^g Toys-R-Us crap that's only good for Quake benchmarks in a production server???
Somebody mentioned 3ware controllers above and they deserve a Hi Five, and Tom needs a slap in his stupid head for not talking about TRUE EIDE based RAID solutions, or maybe he doesn't know the difference. Stuff that Promise, onboard fake RAID EIDE junk because that's what it is. Just look at the cards....cheap, single chip based IC boards built no better than a $5.00, no brand NIC picked up at a flea market. You want data on that?
A 2-channel 3ware card will run you about $100-125, is a true, respected industry solution for RAID services, will do hardware based drive mirroring and run with virtually any IDE drive or PC you can stick it in. In my experience they can almost keep up with the better Adaptec SCSI cards in terms of performance and will whip integrated SCSI solutions, which I hate as well and only find marginally better than integrated EIDE.