Thermostatic shower and mixer taps

Hi guys,
Have decided to get a concealed thermostatic shower unit for the bath plus new mixer taps and shower hose. Is there any constraints in fitting both of these? For instance in order to switch between the thermo shower and the hand held unit is there extra plumbing fixtures required? Am going to buy these online myself so just need to know if there's anything extra I need to get before I get a plumber out to fit both.

they will be two separate units so they can be worked independently of each other, for best results, pipe the shower directly from storage tank (cold) and direct from cylinder (hot). this will ensure uninterrupted feeds, I.E if some one turns a tap elsewhere in house pressure/temperture will not be compromised at shower.

Cheers Davy,
I presume whatever plumber we hire will know to do this anyway?? Sorry I haven't a rashers about this stuff!

Yes they should, but an easy/cheap/lazy way out is just to tee off the supplies feeding the bath, this is wrong but have seen it more then once. By the way, are you fitting a pump to increase pressure?

I was thinking for the meantime to leave the pump out of it Davy as I'm concerned about the size of our hot water tank (ie too small), and am hoping that our normal water pressure will be good enough for the thermostatic shower. Do you think this is a mistake?

not a mistake, however I would instruct the installer to allow for possible inclusion of a pump in the future, hotpress is the most convenient place to locate pump, as hot supply is already there, so it would be a good idea to bring cold supply via hotpress. pumps can also be located in attic so your options are open. A good plumber will advice. Bear in mind also that a concealed shower goes into the wall 4" plus, and then running pipes, expect a mess to be made.
In my own house I have a triton Auqa sensation, its a thermostatic pumped (built in) powershower, a little nosiey and just a white box but performance is outstanding. I have a 35 gallon cylinder which is just bigger then a standard cylinder, and have never had a problem with hot water demand.

Thanks a mill for that Davy. Yeah it sounds like a fair old mess, but I just haven't seen any exposed units that I like. Might stick a post on that tradesmen website for a time and money quote on both options to get my mind made up once and for all.