Ok, so after all that, new router arrived today, and within 20 minutes got everything connected! Seems like they sent me a Duff one 1st time round that didn't broadcast 2.4 properly. Just to make sure, I disabled the 5ghz, linked up all the 2.4 devices first and then turned 5 back on, but I don't think that was necessary now that I have a box that works correctly!
Thanks for your time everyone, at least I know it wasn't me being clueless!
