Here's an twist you can consider.
High flow valves actually help prevent the effects of cooldown by allowing more gas out of the mag, so the gun does shoot more reliably. But the downside is more gas being let out not only empties out the mag faster, but also increases gas cooldown (thereby expending even more gas).
I experimented with this a lot back when I had a Beretta 93R. Firing rapid bursts with it using the stock valves created enough cooldown that halfway through the mag the BBs would land about 5 feet in front of you (it was really pathetic). With wide open ports on the valve (basically taking out 2 of the 4 "sides" from the existing ports) the gun cycled and fire pretty consistently until it was out of gas, unfortunately it often wasn't able to fire off all the BBs (~38 BBs).
But point in case, you can fire off a limited number of shots without cooldown using highflow, which is great if you're using real cap loads. I know its not for everyone, some people still play with hicaps and absolutely want 30 shots out of their pistol... but for those of us who go for realism over munchkinism, it's a great solution.
Something to consider.