I have a VideoMaster for the A500 and Plus for sale. It digitizes video frames in B&W, with audio. For color it uses RGB colored filters. It plugs into the A500 side port. It comes with complete manual.
I also have a MiniGen that works great too. It's for full color use, designed so that you key your Amiga graphics over your real time video. The plugs are standard RCA. It has a switch that allows you to bypass, etc. I've never used this on a AmigaPlus, but I bet it would plug into the side port just like the A500.
Offer me enough to make it worthwhile to box up and ship to you please. Buy either or both units.
Thank you,
Dean (friend me on facebook.com/DeanLach)