I wouldn't get the cheaper wilwoods. Discs are far too thin. You'd be better off with what you have now. I doubt you'd notice much of a difference on the street with your brakes if they were functioning correctly. If you want bigger brakes for the heck of it or you are going to do track work different story, if I had the money I'd do it too, I love big brakes.
The problem with doing brake conversions, is unless you match everything up, you can end up with shitty brakes, no matter the components. A 6 piston brembo kit can brake like crap if you have the wrong master cylinder, crappy pads, wrong front/rear bias etc.
Did you do the brake conversion you have now? What pads do you have? The braking between crappy pads and good pads is pretty significant. Are you brake lines new? How old is the fluid? What is the master cylinder?
Don't get me wrong, if you have the money and don't care about spending it, I'd ditch your setup in favor of some bigger brakes(as big as you can fit). But you'll need to match it up with the correct master cylinder bore and the correct front/rear bias.
Just remember, bigger brakes tend shine once they get some heat in them, which won't happen much on the street.
