Hola, Chris & Jim,
There's a few other places I've just thought about - there's the IKEA (of course) and a Zara Home in Murcia and a DFS store in San Javier (I'm told its the same DFS as at home - you can see it from the motorway) and there's a modern furniture store in the Dos Mares shopping mall near San Javier, although the selection is limited. There's also an inexpensive artwork shop there with a large selection.
There are Carrefour Hipermercados in both Cartagena and Murcia (try www.carrefour.es if your spanish is up to the task). The showhouse was furnished by an interior designer who has a small shop in the Los Narejos shopping square across from the EuroMarina offices. You can see other examples of his work for Taray at http://www.rightmove.co.uk/viewdetails-10432721.rsp?pa_n=2&tr_t=buy&chnl=overseas. Also try website www.mueblesdirect.com who have a store on the road between Los Alcazares and Torre Pacheco near the Polaris World Mar Menor Resort.
We also thought about transporting from the UK, but the cost was prohibitively expensive from Scotland. Also we will probably end up buying a lot of things in IKEA and in comparing prices on the downloaded catalogue(at www.ikea.es) I reckon that Spanish IKEA is on average 6% cheaper than in UK. Also if a fault develops with something you have brought from UK, how do you take advantage of warranties?
Hope this helps!