FIRST: Get new rims, not new brakes. If you brakes suck it begins with your rims not being chrome plated. Second is because your brake cables are not properly lubed - new brake cables are cheap, and MUST be lightly greased/Tri-Flowed. Finally, brake pads must be cleaned/sanded if they are dirty (Simple Green)

Switching your calipers/levers will not come close to making your brakes work as well as chrome plated rims will.

Redline no longer has the engineering staff in place to really produce good product. They buy garbage from Taiwan, stamp their name on it, and when the stuff breaks, don't warranty it. It simply is no longer the same Redline that used to be cutting edge.

Don't even BOTHER with 3-piece cranks unless you are having issues with your 1-piece cranks. You will have ZERO performance increase by using 3-piece cranks, they are stronger - but if you haven't broken what you have, then who cares? A good wheelset will do a LOT to improve your braking and overall bike issues almost right away. Sealed hubs + chrome rims = very smooth ride with quality braking. First thing you should even consider upgrading.

Don't worry about other stuff until your rims are replaced.