In reply to Rog Saxton:
Both areas are brilliant! Tarragona possibly has the better climbing, (Siurana and Margalef), but for me the Lleida area has the edge, because you have the Pyrenees as backdrop and the vultures soaring around you. It also has more choice of altitudes to suit the weather.
I think it would be hard to find accommodation which gave you easy access to both areas. However, if you have two weeks you could rent accommodation in Lleida for one week and Tarragona for the other. Personally though, I prefer taking a camper van. There are plenty of beautiful camping spots near the crags in both areas (though only a smattering of formal campsites open at this time of year).
Have a great time.