Comment by mauvehaus

I'd like to second GP's reply and add that if you get a full-frame mirrorless camera and a couple of adapters, the world is your oyster for cheap, old lenses on eBay.

Figure out what you like on the cheap, and if you want to upgrade to a modern lens, you know what you're seeking for comparatively little money.

Technical version: Infinity focus is determined by how close the lens gets to the focal plane of the film or sensor. The various lens mount standards (some manufacturer specific, some widely genericized) specify the distance between the mounting flange and the focal plane. Mirrorless cameras can have a smaller flange distance than SLR's (because there's no mirror that has to swing through the space), and so you can optically adapt pretty much anything to mirrorless.

Optically being the operative word. You'll lose metering modes that depend on the camera getting info from the lens by either physical or electrical means. If you're shooting landscapes or product, this is unlikely to be a problem. If you're shooting action, you may want to disregard this suggestion.

EDITED TO ADD:

I haven't kept up with the mirrorless world since I bought mine, but if you're doing this get one where the image stabilization is implemented in the body.