Most of the bench top 'mill-drill' type machines have a large drawback in head position not being repeatable if moved for any reason, and they do not have a knee action. Clearance from tool to work gets very tight with a vice, holding a jig, holding the work.
A smaller floor model can be found for around $5k, and will do almost everything you need. Milling octagon barrel flats is about the only thing you need a realy big mill for.

There are interesting 3/4 size floor knee mills that run on single phase 220 current. Most homes don't have 3 phase, which limits what kind of equipment you can run. Yes, there are converters... I guess you have to decide if the added expense of a converter is worth it. But if you look around you might be able to get a used Bridgeport or similar mill in good condition for about $3000. If you're lucky, it will come with some tooling, which isn't cheap to buy new.

You could check out KBC for lower end mills.

I also wouldn't recommend one of those combo mill/drill/lathes. Not for anything where you want to hold a close tolerance.