Hi there, there is a few things it could be, to check, but first need to know whats happening!
     Is your brake peddle -Hard or soft?
                                 -High or low?
     
     Does the brake peddle pump up? Or sink when applied slowly?
     
     Is your handbrake high or low?
   
Or when you say that they're crap, do you mean when driving?
     Vibraites or makes noises when braking?
     Car pulls to one side when braking?

Most common is rear brakes in need of adjustment, which will bring the peddle up and handbrake back down to a few clicks, and also crap fluid, be it full of moisture or air bubbles, and in need of a full bleed and flush.

However, if you want to test your brake booster:-
      With the engine off, press the brake peddle a dozen times or so to remove static vacuum.
      Then, with one foot pressed fermly on the brake peddle, start the engine.
      If the booster is working, the peddle should pull down a little more as the engine vacuum pulls on the booster.

Looking at the few things you said, i'd say the chances are that you may have a few little problems...
     Pulling to the right, and able to lock the right, says that the right front caliper is working, but the left is not(or atleast not as much as the right). Most common problem here is usually an old brake line. The rubber brake line colapses inside after many years, and the fluid has problems getting through.
     By jacking up the front to get wheels off the ground, spin the wheel by hand while someone else applies the brake. If the brake is slow to grab and or release, then most likely will be the rubber brake hose. A sticky or jammed piston is usually shown by only wearing out one brake pad in the caliper.

     Handbrake being high is a case of manually adjusting the rear brakes. This is done at the rear calipers, not the hand brake cable!

     Lastly, if the booster is working and the peddle is high, and after the front left brake is checked, poor braking can sometimes be as simple as having bad pads! I'm not sure what everyone else runs, but i've got Mintex in my road car, and they are excelant.
     P.s. If you don't know when your brake fluid was last changed, i would recomend changing it and giving the system a flush. Is cheap and should be done every 2 years as moisture get in and lowers it's boiling point.

     Hope this helps...

do the cheap simple things first before going all out and buying rebuild kits. There is an order of things to be done you will waste your money this way.

1. change brake pads
2. change brake fluid
3. adjust rear brakes

if its still no good after this, THEN start trying more expensive options.

Ah cool, I was thinking of the last time i looked into rebuild kits for mine but I just remembered I have Volvo 240 callipers on mine, thats why they were expensive to rebuild...sorry about my lack of brain oxygen.