You are going to need a auxiliary vac pump with that cam, lumpy cams and low vac are quite common. Summit has a good selection, but I suggest you go to the Master Power brake site. Look at that pump and try to buy that one, MPB's price is on the high side, however it can be found @ a lower price, so look around.

The reason I like this part are two fold, it is completely self contained and will cut off when a vacuum has been pulled, cycles like a compressor, easy install one wire and a hose to the booster... done. Another suggestion would be mount it under the car, these pump make noise like an electric fuel pump. Get 4 rubber mounts, that are used to mount small compressors, like in a window AC, or refrigerators.

The reason a canister will not work is because the canister will only hold the total vac pulled, in other words it does not build up more then what is pulled. The hard brakes are happening because of the 10 in. of vac the booster needs 15 -18 to work, using a canister will still only give you 10 in, of pressure. These pumps can be found in modern cars, motorhomes, they are more common then I thought, but the prices seem to be about the same and all seem to make noise. I did see one that advertised a DB level but the price was off the planet.

Good luck and let us know what you end up doing, fyi my vac 7-8 @ idle and have been using this pump 12 years.