Well after much deliberation I decided on a new radio and ordered a FRSKY Taranis, it arrived today
It uses the Open Tx software and is 16 channel with either sbus or bind 2x 8ch receivers for full independant 16 channels.
You can even add an external module to get a total of 32 channels
With its umpteen switches, sliders and pots its going to do more than I want at the fraction of the cost of a dx18
Got some learning to do now with the open tx software!
Cheers
Stu