Handheld Shower/diff manufacturer valve and Trim

I've read good things here about the Delta t17t series thermostatic valve (r1000) but I don't like Delta's handhelds. Can I use Grohe's relexa plus http://db.grohecatalog.com/upload/pdf/28917.pdf with delta trim and valve?

When using shower bars (the handheld will be the only showerhead) how is the water released into the hose? Is that the ell I've seen refernce to and would it sit where the exisitng stationary shower flange is in the existing setup? Does anyone know if the part that released the water is included with this Grohe system or do I need to purchase seperately?

I am also considerin Moen. Is their themostatic valve any good?
Thanks much.

It doesn't matter what the brand is on the handheld.

I have installed several Moen Exact-Temp Thermostatic valves and consider them to be very good valves.

The hose threaded connection is probably common, but you may need to match the handheld and the mounting bar company for it to fit in the holder properly. Depending on if this is a retrofit or new, often you can just screw the handheld's hose to the shower head arm. If you want it closer, then you need a trim piece and maybe a nipple to get it to sit flush with the wall.