There's a bathroom showroom on the SS18 just past Santa Maria Del Cedro called Crusco.
Ive never been in but it looks fabulous from the outside with large displays in the windows.
I would imagine that most of the stuff on display would be for order though (and I don't think it will inexpensive! They are listed as stockists on this website which is great for ideas etc but promotes upmarket bathroom fittings
http://www.bagnoidea.com/ - they have an English version too).
Similarly there is a showroom in Cirella called Greco
http://www.francescogreco.com/start.htm
and another in Belvedere also called Greco - could be the same family? (Upstairs in Belvedere are lots of bathroom displays and as they are also builders they probably stock lots of bathrooms for their own ongoing use so "might" have take-away bathrooms)
In Scalea there are a number of builders merchants that sell bits and pieces for bathrooms etc but I don't know their names.
The nearest DIY type store that we have come across is Bricofer in Fuscaldo
http://www.bricofer.it
Last time we were in there they had a very small selection of bathrooms that I would assume were "off the shelf".
Hope this helps, Lesley