ok...the sludge...well it probably wouldnt hurt...if you have the money to replace the MC with a reman one which would stiffen that pedal right up.
Brake systems are really basic if you don't include the ABS controls and such. They are really (* i know i will be corrected) A pedal, brake booster, master cylinder, brake lines, and caliper & wheel cylinders.
therefore...it is not REALLY that hard to solve brake problems, unless ofcourse you are dealing with the ABS.
So, if you really want to tune up that system, I don't think it would cost that much if you did the work yourself. I know i have been meaning to replace my brake system, but I never know what else is going to go wrong being that my car is so old
getting back to the point....
since our cars dont have ABS...unless yours has that option....i would just recommend doing a very thurough bleed. You should be good to go, but hey if you have the money...do whatever you can. Remember: it doesn't matter how fast your car is if you can't stop it.