We are currently using (2) Dual Xeon Servers. 1 for Web and the other for data base. Both have (2) 73gig 10k SCSI HDs, but not raid. We've been taxing and maxing them for the last few months and use EV1.
Later this month I will be purchasing (not leasing) Opteron 270 powered servers. I'm hopefully going to be contracting the server godfather here sometime soon to have a look and let us know exactly what we need, but no matter what it is going to be Opteron. I've studied them up and down and there is little (if anything) that can dispute the Opterons dominance in the server market over Xeons of today (and especially yesterday). My xeons have performed pretty well but with Opterons prices being cut almost in half and their history of excellent performance over the past few years, there is no question in my mind what we're going to now.
I have also studied up on SATA drives, and while they are fast (especially the raptors) in single user environments, they are still a good ways behind scsi in heavy I/O situations such as data base operations. We're going with a top of the line SCSI RAID card and u320 15k RPM hard drives, most likely running RAID 10 for the database. We'll probably use SATA Raptors for the web server running RAID 1. Both will have 2x Opteron 270 dual cores and plenty of RAM. Still undecided on using a Supermicro or Tyan Thunder mother boards..
We will save a pretty nice chunk of change on monthly hosting expenses going from leased dedicated to COLO'ing. I am in Houston but I can't find a colo facility down here that won't end up nailing us on bandwidth fees so I am thinking we are going to colo at
www.dedicatednow.com . They give you 2,000 Gigs a month using a 1u/2u or mini-tower server for $99/mo plus different management plans if you want them to handle that type of thing in house. As we grow, we can keep adding servers as needed. I'm really tired of leasing servers and will be happy to purchase our own where I know the history of the equipment (we've had two hard drives go bad in the last 4 months on the same server) and it doesn't cost us a huge amount of money each month to have really powerful machines. If we want more RAM, we pay once rather than a setup fee and then a monthly.