this is a little over budget but its worth it, this is the best pc for this price you will be able to get unless you build it yourself
http://www.overclockers.co.uk/showproduct.php?prodid=FS-025-OP&groupid=43&catid=2040&subcat=
you will be able to run over 10 bots with that system.
System Specification
- Case: Antec 300 Gaming Case - Black
- Power Supply: OCZ StealthXStream II 600w
- CPU: Intel Core i7 950 3.06GHz Overclocked to 4.00GHz
- Motherboard: Intel X58 (Socket 1366) DDR3 Motherboard
- Cooler: Corsair H80 CPU Cooler
- RAM: 6GB DDR3 1600MHz Tri-Channel
- Hard Drive: 1TB HDD
- Graphics Card: A choice of the latest graphics cards all 1gb+ can pay extra for 2-3gb cards.
- Sound: 7.1 Channel Sound (On-Board)
- Optical Drive: LG DVD+/-RW SATA Drive