aer lingus used to go direct to toulouse but not sure if still doing it (it was in summer i think), ryanair go direct to biarritz (train takes roughly 3 hours from there to lourdes) or ryanair to Pau Pyrenees via Lon Stansted (from Pau, train is only about one hour i think).
lourdes is a lovely town i think if you can see past all the souvenir shops. The funiculaire to Pic du Jer is nice, you can get funi up and walk down if you wish. The walk around the stations of the cross is very nice too with great views. Enjoy!