Thanks for all the advice guys.
Looks like I will go for the Impey option, tho not cheap it seems to be the most straight forward to fit.
Went to the tile shop today to look at some travertine tiles, guy says they are heavy tiles and if fitting to a stud wall they recomend re inforcing the wall !
Anyone got any experience of this ? Seems a bit OTT to me but then again I am fairly new to this game
Also would the tiles drag off the tanking membrane?
Cheers Rich