Well that's handy that you have somewhere to stay until the big day looms. Makes a big difference in that you can make sure everything is done to your satisfaction before you part with the rest of your money.
Also you can take some of your stuff over each time you go making full use of the airlines baggage allowance.
It's amazing how much you will still be taking over each time you go, I still have loaded cases after 4 years. In between visits I see things which I think I'll need in Spain and start packing a case for my next visit. Each time I tell my husband that this will be last time that I will need to take a case but he shakes his head knowingly.
I don't know if you have a Poundland nearby but they do small round touchlights (pack of two) which are battery operated. I have these all over the house as I think they are safer than candles and you can carry them around with you if necessary.
When you have a power outage it's quite frightening how dark it is, after my first and only one at night I went out and bought small torches and candles. Now though I can reach out and find the touchlight on the coffee table so it's much easier.
Whenever I'm over the power seems to go out during the day but it's better to be safe than sorry.
Hopefully the others who have bought in the area will be able to help you further. If your air-conditioning has been pre installed it should be quite easy to get a quote as the wires will already be in the wall.
Best advice seems to be from others who have posted on forums is to get your grills fitted first and then arrange for the furniture etc to be installed. Most firms in Spain allow you to pay a small deposit and then you can either go in to arrange delivery and pay balance or pay balance to delivery driver in cash. Even Carrefour do this! Very handy if you see something you want but are not carrying your cards or enough cash with you.
I found these forums after I moved into my house but I was lucky in that I had neighbours who were able to help and advise me, not all of the advice was good and I had to follow my instincts. Your parents have been there done that so you have a head start.