I can relate to this. Tried it around a year back, really wanted to like it, but unfortunately the search results are pretty much useless..

You have listed some good options there👍 One additional possibility: what about repurposing an old enterprise workstation, like Dell Optiplex, HP Elitedesk, Lenovo Thinkcentre etc.? They can be bought for around 50-100 e/$. For a similar use case I've been running an Optiplex 7010 SFF (Small form factor) with i5 3XXX and 16G of ddr3 and it has been plenty of powerfull for the purpose.