I would go with Spain over Portugal since the climbing and food is better. If you want to meet up with others then maybe Costa Blanca or Siurana would be the best bet as they both have climber bunkhouses (El Chorro does (La Finca & Olive House) but September might be a bit too hot). Both would probably be easier if you had a rental car.
The only place to stay in Costa Blanca if you want to meet others is here:
they are very friendly and as it's a bunk house i found it possible to hook up with randoms there (who are more likely to be English speakers than Siurana)
haven't heard good things about the refuge but that may have changed. Although Siurana has a reputation for its hard climbs, there is plenty to do at 6a-c ie your grade range.
Costa Blanca would probably offer more from a low-mid grade point of view. Worth posting for partners on UKclimbing. Also consider one of the organised weeks that the OH and places like:
CB probably has more trad options such as the Puig de Campanga which is right near the Orange House, but i wouldn't take a whole trad rack just for this. PM/reply me if you need more info.