Vacuum Canister versus Vacuum Pump

[LuvNLife]

I went to look at an '86 2wd shortbed today. It's running a 468 with a fairly radical cam. The owner did caution me about the brakes not having enough vacuum to operate correctly, but even at a low speed, it's kinda hairy stopping. So, I know it would need either a vacuum canister or vacuum pump. The cost difference - $70 versus $275 is pretty steep, so hoping to hear from folks with real-world experience with either or both. I know I'm going to make an offer on the truck; just trying to budget and plan ahead.

Thanks,

Jerry