Ty - I made the vacuum pump from an old compact refrigerator compressor. Google it and you'll find a lot of info. I incorporated a vacuum controller that shuts-off the compressor when it reaches a certain vacuum level and turns it back down once the vacuum leaks down some. There's some hysteresis involved, so it doesn't cycle constantly. There are free detailed plans for a few different styles of vacuum pumps here: https://www.veneersupplies.com/pages/DIY__Vacuum__Press.html
Duck - Thanks. The makeshift bags are pretty tough. I've been using some smaller tube-style bladders for years.