It seems to me it would be easier just to buy the EZ vac systems and get everything you need to start bagging. By the time you scavenge all the parts and buy a pump you would have spent a lot more than the cost of the EZ vac system.
https://store.acpcomposites.com/ez-vac-systems It's a lot easier to just take it out of the box and plug it in and use it, than trying to put one together just to save a couple of bucks, (which probably wouldn't happen anyway)