Diverter Valve for new shower

[affro]

Hope somone out there can help me.

I'm about to install a new mixer shower, I have bought a shower cubicle which has a fixed shower head and also bought a Hansgrohe Marin Centrostat thermostatic bar mixer shower.

Problem I have is trying to source an exposed diverter valve that will attach onto the bar mixer and allow two flexi hoses to attach onto it. I've found plenty of built in diverter valves but can't seem to find any exposed ones that are suitable.

Anyone got any bright ideas??

Thanks for any help you can give