Hmmm, That's a similar issue I faced recently. I had to build a custom machine as there isn't much in the market that fits the "big, decent quality, reliable, easy to use" market. There's a whole bunch of cheap machines, some of which work decently and some of which ....don't. There's a handful of machines that are reasonably high quality, generally easy to use, and reliable, but usually with smallish build volumes (Prusa, Flashforge Creator). Then there's the high end machines, with associated price tags.

Perhaps check out the Artillery Sidewinder. It's very well priced, but also not too cheap. It has a fairly decent design and is a well balanced machine, with a hotend and extruder design that matches the build volume. More importantly, from what I've seen, spare parts and support are easily available, and there's a decent community that can offer support. Firmware appears to be maintained on github, and is a Marlin version.

There's a lot of other machines out there. Just try and check that there's decent community support, and watch out for machines that run a custom firmware that is difficult to update.