Travel Spain-costa del sol w 2 kids

Hi,

we were planning on renting an apartment in Sitges, Spain for a few weeks in July but the prices were around $5k. We have now switched gears and are looking for a place to rent somewhere on the coast, Malaga, Marbella, etc.. The rentals for 1 bd apartment are soo much cheaper (which was very shocking to us) Costa del sol is pretty big and we are not tied to any particular area.

Can anyone recommend a specific area that would be good for 2 children aged 6 and 8. I think i want an apartment rental that is part of a resort w pools, bar, etc instead of renting a private house. Our cousin lives in Barcelona and is a travel agent but really is not helpful.. I think she more or less just sets up excursions for tourists.
The last time I was in Marbella was 10 yrs ago on my honeymoon.

Thank you in advance for any and all help, recommendations, tips, etc!