Inside Right are a UK based company who have serviced the new build market in the UK for many years & have now opened up in Balsicas. We have found Gareth the manager at Balsicas to be very helpful & obliging - they have packages over 3 price points, but are happy for you to pick & choose which items you want. They keep stock of most of the items in Spain so are able to turn around pretty quickly. We also visited Villapac at Milton Keynes, the only disadvantage we found was they do not have a showroom in the Murcia area so everything had to be selected in the UK. some items were cheaper & some dearer than Inside Right. Inside Right also supply & fit Lights, ceiling fans etc & offer a lock changing service.
If you are not looking for a package , but to buy items individually Changing Rooms in La Zenia are very good & very reasonably priced. They also have the advantage with a lot of their sofas etc that if something gets damaged they can generally replace parts of it, an added advatage if you are renting out
Ikea in Murcia is very good for finishing touches & obviously very reasonably priced
Hope this helps.