I would recommend TODOGAR in Torrevieja for value and service if you want a one stop shop. It is true that you can get everything separately going to say Media Markt, Lee Roy Merlins and furniture outlets or Ikea, but I found Daniel at the store very helpful and open to a bit of bargaining.
They deliver and fit everything like most furniture stores in Spain (except Ikea who have a delivery and assembly price list - but they do not put up lights). Daniel speaks excellent English and the packs, which can be varied and modified, include all your basic equipment down to the mop and bucket! Very handy when your apartment is a holiday home and you don't have a lot of time after signing to shop around.
They currently have an offer on hot/cold air conditioning through a partner company - Johnson units - E339 for bedroom and E369 for lounge - fitting around E185 each or less. I have friends with Johnson units and they are good quality I believe. I have been advised that if a property is south facing the compressors should be kept out of direct sunlight as it affects the efficiency. I plan to have mine on the floor by the inside wall of my solarium in the shade. This will prevent an eyesore and hopefully ensure they work well.