Montserrat:
It seems like the best place is Montserrat, most websites say it's world class. There are over 1700 conglomerate routes there of all levels, most of which are multi-pitch (3-8 pitches) sport, very very few of which are trad, due to the nature of the rock. It's a national park, and it has a town/monastery on the mountain where you can actually rent out apartments. The bonus is, all the guidebooks are available online (http://rocktopo.com/index.php), in PDF format. We still have to pay, but we don't have to wait on shipping, which is a bonus. Montserrat is also accessible by car or train, so we could stay in Barcelona and either train there or rent a car (two, really, seeing as how many of us there are now) and drive. It's a 1h11 train ride (17 euros return for an adult, and cheaper if we get group rates, week long passes, etc...) or about a 50 minute car ride (usually cars are about 250$ a week over there, and we'd need two, so that works out to about 9$ per person).
Rodellar:
There are 220 limestone routes in Rodellar, most of which are 7a and over (5.11d+), and very few under 6a (5.10). Routes are around 200m long. If we all turn into Hulks by then, maybe it would be worth going, but warming up on 5.10 lead is not exactly my idea of fun. Camping is the only option here, and we would need a car to get there (3h30 drive).
Riglos:
There are 164 conglomerate routes in Riglos, with an even grade spread. Routes are around 300m long, however, many require a trad rack. Camping is the only option here as well, and would also require a car (4h00 drive).
Siurana:
There are 635 limestone routes in Siurana, with most being 6b+ (5.10d). Routes are all less than 100m long. The guide says that this is "a place to push your limits, but not really for beginners", whatever that means. Camping is the norm here, but there is a hotel available (140$ a night for a double room). It's about a 1h45 drive from Barcelona, and the guide recommends renting a car rather than taking the train down there, as the crag is very far away from where the train stops. Obviously, we would want to stay here rather than commute each day.
Montsant:
This area is right next to Siurana, and is a national park. There are 45 limestone-coated conglomerate routes here, with the easiest grade being 6a (5.10a), and most being 6b+ (5.10d+). Same accommodation and transportation situation as Siurana.
Barcelona proper:
There are two places to climb in Barcelona, both parcs. The first is Guell parc, it has a few walls and a long traverse. The second Montjuïc, which has a tunnel that was converted into a climbing area. This means that on a rainy day, we can go climbing there, which is pretty sweet.