I have both future pinball & visual pinball with a bunch of roms but i belive the same thing as you do, they won't run proper without a proper graphics card and alot more ram. Might as well put the energy elsewhere. I am working on my own cocktail table with an old 28" television and a computer. The main purpose is to be able to play pinball on it. Might be neat.
regaring the ibm disks, I used them because those were the ones I had laying around. Might upgrade later, but i still have a full backup of it so it won't be any trouble if (when) it crashes.