Okay feel free to ask questions here. I would say build your own. Thats a lot better then buying and dual xeon machines are hard to come by when you buy prebuilt. Now if you give us a budget we can probably give you everything you need from a trusted site like www.newegg.com.
Or you can do it yourself you going to need these things
Dual xeon motherboard
2 xeon cpus
case with powersupply
thermal compound for the cpus
Basically thats everything you need, you can research em and post uip everything after you have it configured or i can do one for you for a budget.
P4 2.26 ghz, Intel d850emv2 mobo, 768mb of pc800, sony 4x dvd-rw, teac burner, nvidia ti4600 graphics, enermax 330watt ps
4 silent uv fans, cold cathodes in full tower antec case, round ide cables
SOny vaio 2.66 ht ghz modded into raidmax case with green cold cathodes.
P4 2.8ghz HT, 512mb ddr, Intel KD865gbfl, onboard video, raidmax case, blue cathodes, round ide, loomed wires, 4x dvd burner, wd sata 80gb hard drive
Intel d865perl, 2.8ghz northwood, antec sonata, wd caviar 20gb, Corsair 512mbx1 for now. 380watt psu, ati 9600, dvdrom cdrw floppy in black too match case