Hey,
> Recommendations as to what "functions" to set each server as (DC, file server, combined, etc)
If you have two servers, promote them both as Domain Controllers. If you don't you don't have total resilience in the network, which could cause problems in the future. The AD DS roles don't utilise very much - if anything at all - anyway, so it shouldn't make a difference to system performance.
> Which server you would reccomend
If you are comparing between those two Dells, then I would definitely go for the one with the Xeon processor in it. Those are very reliable units for servers.
> Recommendations of RAID 0 vs 1, 10, etc.
Do NOT use RAID 0 on a production system. This goes backwards in terms of redundancy - you have two drives storing the data, and if either drive fails, you lose all the data on the array. At least RAID 1 should be used (two drives in a mirror), or if you can afford it, RAID 5 or RAID 10 for both performance and redundancy.
> 64 bit OS vs 32 bit
Which version of Exchange do you intend on installing? If Exchange 2003, then you must have a 32-bit Server 2003 Operating System installation. If Exchange 2007, then you must have Server 2003 x64 edition installed. If you can, go for the 64-bit, but remember that if you do go for 32-bit, it CAN run on a 64-bit processor (the CPU just works in 32-bit mode).
> Recommended processer, # processors, amount of memory
It would be a good idea for probably a quad core Xeon processor, dual Quads if you can afford it, and 4GB of RAM should suffice. Bear in mind 32-bit OSs cannot address more than 4GB RAM, and Server 2003 Standard Edition is limited to 4GB in software.
-tigermatt
