My wife and I rented two Trek electric bikes for a five day biking trip through the Costa brava. We rented from Trek because they received such high praise for their customer service. Unfortunately, our bikes had a couple of technical malfunctions, which was no fault of the trek store and Carlos the manager took care of us 100%. In one case he even brought out a brand new bike to replace a bike that had a faulty battery. We would definitely rent from them again and Carlos was excellent.
I highly recommend electric bikes if you are biking the Costa Brava from Girona as the hills from town to town are quite steep. The bikes we rented from this location, had more than enough power to handle the very steep Hills.