Your best bet would be an Apple Macintosh Power PC with dual processors. Chances are that your competitors are using this also, as the Macintosh was designed for this type of use from the beginning. You are in the only group I would make this recommendation to, as it is a relatively high-cost option. A dual-CPU power-PC will (on applications optimized for it) outperform an Intel-class machine running at 2 to 3 times the clock speed.