Well, As far as I know, RedHat is the most popular, still if u are prettending to do some hard, big, crtical resource eater, you should think on a distro that lets you modifi everything in a easier way.
Still RedHat uses SystemV as default to boot, and SystemV Isn't supposed to be modfied by hand.
I would prefer a BSD boot system that Is intendet to be intuitive to be modfied by hand.
I should chose Slackware, for that, well maybe Slackware wont do anything for you, you will need(I LIKE) to do almost everything by hand, so If you can get the sources, you can make it run.
In performance, well, Youcan make it run, In the way U like.
It's a matter of taste... I you know hot to compile a source, you probably could run any program on any distro, the problem goes with the propietary programs.