If I went again, I'd definately stay in Santa Eularia.
We were down the road in Cala Llonga, but S. Eu is quite cheap and there's plenty of nightlife there.
It would be a great base to stop at, with good road and ferry links to the rest of the island.
I don't think you'll be disappointed! Of course, I've never been to San Jose, but it's further north so, for clubbing, you'll be a little further away from things (although the beaches up there are supposed to be v good).