Final question (I hope) and I'm really just looking for reassurance
here
I've never used plastic pipe before, but I'm thinking that it might
make my life a lot easier with the connections from the Hot and Cold
tanks to the pump. I assume there are no particular problems with
mixing and matching copper and plastic pipe ? I'm thinking that I'll
use plastic on the inlets to the pump and copper on the outlet side,
simply because most of the pipework on that side is already in place
and in copper.
Any particular pitfalls I should look out for ?

Thanks.