Hello AJW,
Options for extras such as white goods and such should be readily available for you to price and view during your trip (depending on who it is with of course). Polaris World Homestyle is a part of the business that can take care of that for you but I suspect they might be expensive and as these products are all standard sizes, I would be tempted to look at some local retail outlets too. The other side of Murcia city are many good retail parks that have loads of this kind of stuff (25 mins away).
In the Jardines apartments, the oven & hob & extractor hood are all included - there is room for a fridge freezer and a washing machine but not room for a dishwasher (after you complete on the property - you can of course fit one but at the expense of a cupboard). There are some images of the kitchen that i can send to you if you wish - it is an american style kitchen (which means that it is entegral to the living room with a counter spearating them).
Regards room sizes, Polaris World are loathe to publish them but in fact the bedrooms are a reasonable size (generally all Polaris World rooms are similarly sized). When you visit the Polaris staff are very knowledgable and can give a very good idea of the size of your rooms by comparing to the show apartments. The bathroom is a good spec and ok size too. They will be able to demonstrate paint finshes, tiles, bathrooms, wardrobes,e tc that are exactly the same as you will buy.
It is very easy to buy from this developer as they are very professional - but take your time and be sure. Come back to me if you need any further advice. I know this company very well and own 2 Polaris World properties myself.