Quote:
I can sleep on my side with my Shure E5's

Wow, expensive!

However that does remind me, one possibility is something based on an Otto acoustic tube driver. The advantage of this is that you might be able to form the tube around your ear and into the ear canal without any sort of ear moulding. It might fall out when you are asleep but the tubes are very soft so you won't notice.

You can form the tube with heat or you can get tubes with embedded wire that might also work.

I think you can split the tubes from a single transducer but they are only about $30 each so you could get two.

Gareth