Let me chime in with an experience pretty similar to yours. Machining is definitely a hobby for me - not a career - and I also live on a farm. Started out as an equestrian operation but when I got too old for the young colts, we converted to beef cattle. Like you, farming was not my income source, but a very enjoyable hobby. My largest tractor is also 75HP, I have two other tractors, other heavy equipment and a boatload of farming attachments. I got interested in machining because of watching a machinist make a couple of small parts for me. That was enough to have me hooked. You're wise to not take on the challenge of buying an older Bridgeport or clone that needs a good bit of work to achieve the tolerances you need/want. Been there/done that - not a good idea for a rookie, especially if rebuilding it is not your main interest.
Having said that, let me offer a couple of comments.
First, you may find that you're underestimating the optimal size and capacity of a satisfactory machine. I now have a full size Vectrax machine that I bought used in pristine condition complete with power feeds, DRO, etc. I have less than 10K in the machine including upgrades to a better DRO system and other peripherals. Like you, a primary interest for me was maintaining farming equipment, but that has morphed into far more interesting non-farm related projects and applications. You'll find that the size and scope of your projects - both hobby and necessary - will, to a large extent, be dictated by the size of your equipment. To a point, bigger is better.
Second, wait'll you discover how many new friends you'll make when neighboring farmers realize you can fix a piece of equipment! If your farming community is anything like mine, there will be occasions when a farmer is down because a piddly little part has broken, and he has a crop in the field that needs to be harvested NOW. One of the features I like about living in a community such as ours is how willing neighbors are to help each other when the need arises. There have been some instances in which I could not have gotten a farmer's piece of equipment up and running with a smaller machine. (There have, in fact, been a few instances that I could not help because of size constraints.) But it's all good. Like they say, what goes around comes around. I've never come up empty-handed when I needed a little help from somebody else.
Also, like you, our area is pretty sparse of decent used machines. But if urgency is not a constraint and you don't mind a little travel, you likely will find a bargain. My Vectrax, in fact, came from your backyard in Montgomery, AL.
And I don't recall seeing anything on this thread, but don't rule out the likelihood that in the not too distant future, you'll be looking for a nice lathe. Again, the bigger you can find, the better.
Regards