As mentioned, you're main concern really isn't supply to the PCs, as long as the line voltage quality is acceptably consistant. Power supplies for both PCs and audio equipment are extreemly well designed these days, and the engineers who develop this equipment take into account reasonable fluctuations in voltage, harmonics, and line spikes.
Server rooms will require specialized supply, isolation, distribution, backup systems, HVAC work, etc., but that's a whole diffent thread.
As Steve and e57 mentioned, your main concern is what ELSE people will tend to plug into the PC circuits. If possible, dedicate circuits specifically to the PCs and label them as such (then sit back and see how long this is actually observed by the user). This will be difficult in a partition farm with integrated outlets, but it can (and should) be done if the business owner finds the cost acceptable.
