To close the loop:
Daytrip.Com was on expensive side.
It's a company in Central Europe going through couple of middlemen. They also had issues with stops and advance payments
So we ended up using Fernando Batista of PortugueseChauffeur.com
UK educated (excellent English obviously) running a family business in inter city transfers and private tour. Excellent knowledge of Portugal history and very professional.
Highly recommend him.
(PS: He gives RS forum members small discount - just ask for "keni" discount)