An interesting proposition. Zamani experimenting with vacuum pumps...
The reality is that the brake booster is just a convenience. It is not an essential item in the brake circuit. The fix is removing the booster and all the paraphernalia that makes it work and replacing it with an appropriate brake pedal length ratio that provides sufficient leverage to operate the brakes. To save weight my race cars do not have boosters and the brakes are much bigger that the street car equipment. HOWEVER this is all too much stuffing around for your basic requirement so go the vacuum route. If not electric, there would be belt driven equivalent vacuum pumps.
Special note for Zamani. Mate, I know you are a hands on kind of guy but I am telling you, the idea of using a hand pump and the steering wheel at the same time might be cheap but it has serious pitfalls.
We all need a laugh don't we?? !!