Haven't quite got around to sorting this yet. Was looking at the 9200 as I said but there's some issues with the wiring that someone is looking at for me. Also looked at a headunit replacement, but the same wiring issues are there for that.
Someone is working on a harness adaptor that would let the car's built in sat nav work fine with a non-standard headunit so I might wait until that's ready before doing anything. Plus who knows what Monday brings with Apple?
Other idea was to get an Alpine Ex-10, which is like a non-permanent 9200 that I can pickup for £50. PRoblems being it doesn't charge the iPhone unless you buy an adaptor. Still, it's cheap as chips.