1. By new kitchen, I assume you just mean the white goods rather than kitchen units
2. White goods are about the same price in Spain. We bought the following:
a. Electric fan oven
b. Ceramic hob (touch control)
c. Zanussi Washing Machine
d. Bosch Dishwasher
e. Large Fridge/Freezer (good make but can't remember what it is-similar to a Hotpoint in UK with wine rack built into fridge, auto drawer opening for meat, ice maker in freezer)
f. Russell Hobbs 4 slice bread/bagel toaster
g. Automatic Fruit Juicer
All for €2,000 which included delivery and fitting. (I know, the fridge doesn't take much fitting but the hob and oven did). You can buy cheaper but we went for top range items as (hopefully) will last longer.
3. Yes, as most items in the EU are made in the Far East they are interchangeable between all EU countries so your hob and oven will work.
4. Can't recommend where to go as you have neglected to say whereabouts in Spain you are going to.