Super Micro Computer, B.V.
Het Sterrenbeeld 28, 5215 ML,
's-Hertogenbosch, The Netherlands
General Info: Sales@Supermicro.nl
Tech Support: Support@Supermicro.nl
Supermicro uses Xeons in all their current workstations. You'd have to ask for a custom job to get Opterons in a pedestal build. Nothing says you can't just run http://www.supermicro.com/Aplus/system/2U/2042/AS-2042G-6RF.cfm on its side, except it's going to sound awful in an office. If you're curious how one of those could/would spec out filling all bays and memory slots (without converting currencies),
1 x SUPERMICRO AS-2042G-6RF 2U Rackmount Server Barebone Quad Socket G34 AMD SR5690/SR5670 DDR3 1333/1066/800 Item #: N82E16816101321 $1,899.99
6 x Western Digital RE4 WD5003ABYX 500GB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive Item #: N82E16822136697 $449.94 ($74.99 each)
32 x Kingston 8GB 240-Pin DDR3 SDRAM DDR3 1333 ECC Registered Server Memory Model KVR1333D3D4R9S/8G Item #: N82E16820139140 $3,103.68 ($96.99 each)
4 x AMD Opteron 6128 Magny-Cours 2.0GHz Socket G34 115W 8-Core Server Processor OS6128WKT8EGOWOF Item #: N82E16819105266 $999.96 ($249.99 each)
Subtotal: $6,453.57 which is about the total budget.
The biggest problem with Opteron 6100's is the next faster proc costs 2x as much. I'm not suggesting this exact config, just an example. And YMWV with exchange rates and the hike to costs when importing stuff to your lil island. The UK gets hosed on hardware prices.