Hi! First, e-brake uses the rear wheels to slow the car down if there is a hydraulic failure. As for the 'brake noise', are you sure it is coming from the brakes? I will take the wheels off and see if there is a small rock got stuck between the pad n disc. next, i would find a down-hill road and put the car in neutral n release the hand-brake, then let the car roll and then see if u hear any noise (make sure you do it when there is not car or house around, just in case). if there is noise, i dun think it's your brake that goes wrong. it might be the wheel bearing.
As for the brake upgrade, rotora is good, but what engine are you planning on swapping?? I just did a z32 brake conversion, and it stops pretty good.....I would prefer z32 front 4-pot caliper and 2-pot rear caliper, and z32 brake master cylinder. ppl been saying that z32 brake is good enough even w/ rb25 swap.
http://importnut.net/300zxbrakeswap.htm
here is a website that has the 300zx brake swap w/ the s14. S13 is about the same except one is 5-lug, and other is 4-lug. you can re-drill the z32 rotor to 4-lug.