They are all basically the same, they do the same job, store energy. Find the size you need and chances are it will do the job it was made to do. There will be no audible difference regardless of what brand you go with.
what about the differance between a 16v cap and a 20v cap? i used to have a 16v rf cap and the volatage was usually like 14.3 or so with the car on and now all the caps are 20v and my voltage is like 14.9 - 15.1 just wondering if there is a differance in them