Aric,
Even if you can find a decent 3/4 player, your tapes are so old they may suck, but then, 3/4 sucked to begin with. Digibeta would be the best backup, but what a cost to backup something that is so awful to begin with. If any of your footage is decent, I would just keep digital copies, uncompressed or ProRes, NOT DV.
To capture 3/4 to uncompressed, you’ll need some kind of SD card, BM makes a pretty good cheap one. You may need one that’s PCIE if you get a new machine.
To copy the tapes to Digibeta, you don’t need a card.
CRTs are available on eBay, but there are some decent LCDs and plasma monitors, but they can be pricey. There are a boatload of threads on monitors in the archives here.
Have a wonderful day.