Hope I can help you!
Nova Vaga is the official kite beach in the Lisbon area, located in the south of the Tejo river, in Costa da Caparica.
Close to it, there are same others very nice kite spots, like Lagoa de Albufeira and Troia.
One of the resident kite schools in Nova Vaga, Kite Temple, has specific packagings for kite trips to Portugal: accommodation, downwinds and kitetrips to the spots.
You can find more infos in http://www.kitetemple.com/kitetrips.htm
Contact Kite Temple, IÃ¢â‚¬â„¢m sure they will be a great help and a great choice for your trip.
And yes, I recommend Portugal!!!
Hope see you in May! Stay in touch!