After a depressing amount of research it turns out most '75 ohm' cables are actually 75 ohm coax with 50 ohm connectors. I was worried about compatibility as how the insulation and center/shield ratios are different. I believe the connector on the camera is 50 ohm specked one?
Tried using coax and while it looks like a great and makes for easy lead construction(That you can buy pre-made cables), I've found that it's typically annoyingly heavy and stiff.
Been using simple twin speaker or audio wire, picking based on feel and what I can get easily. Soldering to the BNC connector is annoying(You can get ones with terminals but they don't look as good) but the finished cable is light, portable and if I had my camera handy I'd take a photo.
I do also recommend spending the extra to find a switch with a nice positive 'click' when you push the button. It works fine with even touching wires together, but without the 'click' I've sometimes missed shots thinking I've hit the button but didn't or didn't realise I'd triggered it already.