Calgary Chris, I agree with Bill, why are you considering changing to manual brakes? It will be a lot more work than you think. It's not just pulling the booster off and bolting the M/C back on. On a manual brake car, the M/C mounts 2" higher and the pedal push-rod pin location is also 2" higher. I know this because I went the opposite way, from manual drums to power front discs. Believe me it's a lot of work. An electronic vacuum booster would be the best way IF you will not consider a more streetable cam, as that's your real issue. Believe me, with all the "couldn't care less about you" idiots driving our streets these days, you want all the braking power you can get.......... ask me how I know!!
The booster that is shown is quite expensive and looks to be a bit more complicated than the one my friend has, which tells me there are options. Do some research and post what you find.
Geoff