I'm looking for ideas for connecting encased devices. So PCB -> Panel <-air gap-> Panel -> PCB. Better: Free end (for crimping connector) -> Panel <-air gap-> Panel -> Free end (for crimping connector). I'm just looking to transfer signals and low-current, low-voltage power in a cheap way. Although PCB edge-mounted connectors are an available option, I can't use these.
An example solution would be an IDC connector with flat cable: flexible with a variety of potential contacts and easily obtained with pre-made cables. It's easy to find PCB mounts and male/female connectors but a panel mount socket (or plug) seems non-existent.
An alternative would be d-sub connectors. Again, variety of potential contacts, easy to solder up, but quite large. Easy to find male/female connectors as well as panel mount. Cheap as chips, but quite large.
I've come across pluggable terminal blocks but these are expensive.
The hardest element to find seems to be the panel mount socket (except for d-sub) but I'm not sure that I'm searching with the right keywords. It's even harder to find a panel mount socket that is not expensive. I'd settle for d-sub but thought I'd throw this out there for ideas.