It looks like I'll be in the market for new server hardware ASAP, and from past comparisons, recommendations, preferences, etc, I'm looking solely at Opteron systems, and primarily Sun hardware. Both usagijer and solipsistnation have sung the praises of the Sun Fie V20z and V40z. But I'm also looking at the X2100, X4100, and X4200. The plan is to run VMware ESX server and primarily Win2k3, with some Linux (probably CentOS). Right now I think the X2100 is probably too low end, but it is cheap. I'm most likely looking at dual-core Opterons in whatever I get. The other issue is it isn't clear if the x2100 and x4100 support ESX. The v20z/v40z definitely do, and the x4200 is in the list - but it looks like only in boot-from-SAN. I'm kind of leaning towards a v20z with two dual-core Opteron 270s. I'd like to max it out with 16GB RAM, but maybe just 8GB to start considering the cost. All told it looks like it'll be $10k or so.
So, anyone have any input on these five systems? Feedback, good or bad, is welcome.