Cheap fixed focal length lens for Pany GM1? Goal: low light capable portraits w/ creamy bokeh

I'm not sure how those AF lenses work on an m4/3. You might need a rather specialized, expensive mount which would negate some of the advantage of the low money that these lenses cost. I use an old Nikon manual 50mm 1.8 lens with a cheap, very simple type adaptor on my camera and it works very well. I haven't used it for portraiture exactly, but mostly for musical performance stuff and I really like the look that I get with it. It doesn't seem to be quite as sharp as native m4/3 lenses, but it's still pretty good. It also doesn't seem to focus well at infinity, but if you're using it for stuff like portraiture that's not going to matter anyway. It's definitely possible to get some really nice blur/separation with this lens and a 1.4, if you can get one would allow for even more of that.

Some other folks will know better than me which are the very best 50mm lenses to use, but those old 50mm lenses were the ones that came standard on 35mm cameras back in the day and are really common... and fairly cheap. it's a bit short for a portrait type lens on the 35mmm format, but for m4/3 where it works as a longer focal length, it's perfect for that kind of thing. Most of those old 50mm lenses are 1.7 or 1.8 but there are of course 1.4 and 1.2 lenses as well... and you might luck out and find one of those for cheap, but typically they sell for quite a bit more. The more standard 1.7 or 1.8 lenses will probably work fine for you though....