Does anyone (clarion?) still make head units that can connect to the cd changer?

Is it some sort of standard connector I should be looking for?

I don't want to spend a fortune on it but my old head unit is getting a bit flaky and looks a mess (never had a box for it so it's got knocked about a bit in the glove box).

No. Even a new clarion will not work without a very expensive adapter.

Even a fairly basic new head unit will play mp3 cds, one of which will be able to store more than a 6 disk changer.

More room in the boot I guess, but I do like the idea of a cd changer, feels posh

I'll probably join the 21st century and get something with bluetooth, plenty of room on my phone for mp3s.