Brake boosters - looking for help on a couple of fronts

Alright fellas and gals. I have two bicycles. A Santa Cruz Chameleon hardtail and a Santa Cruz Superlight full suspension. Both bikes are from the 1999 and 2000 era, right before discs became the norm. Needless to say, neither of my bikes include disc brakes and I am unfortunately not in a financial position to outfit them both with disc brakes, so please no recommendations to move to a disc brake.

All of that being said, I have some questions. First, I feel I should tell you more about the bikes and how they are outfitted right now. The Chameleon is set up for singlespeed with Avid Arch Supreme Ultimate v-brakes and Paul's Love Levers. The Superlight is outfitted with Magura HS33 hydraulic rim brakes. I recently purchased brand new Evo2 master cylinders/levers and stainless crossover lines for the Maggies.

I am trying to spend a little bit of cash to make the brakes the best they can be until such time that I can afford the move to disc brakes.

Question #1 - What the hell is a 4-bolt brake mount? From what I have found, it seems to be unique to trials bikes. The reason I ask is that there seems to be quite a few brake boosters available for 4-bolt mounts. Will any of the 4-bolt brake boosters work with the V-brakes/canti studs?

Question #2 - If the 4-bolt boosters won't work with v-brakes, any ideas where I can find a good v-brake booster? It seems they have been discontinued, leaving us V-brake users out in the cold. Any ideas, would be most appreciated. Hell if anyone has some used ones laying around, I would love to buy them from you.

Question #3 - My final one. I am looking for an alternative aftermarket brake booster for the Maggie HS33 rim brakes I am running? While I am currently using the standard steel ones, they seem kind of flimsy, and I believe that the brakes would benefit from a beefier booster. Again, any help would be most appreciated.

Thanks for the help fellas and I look forward to your responses.