I've been to both Spain and Portugal. I wasnt impressed at all with the courses in Portugal. Unless you pay mega bucks (San Lorenzo and the like which are €140 a round), you will be playing on poorly kept golf courses (Vila Sol, Vilamoura and yes your eyes do not deceive you Quinta da Lago- all around €80 a round) whose main aim is to put out as many golfers as possible and make as much money as possible. Basically its a crammed 5 hour jaunt in 40 degree heat (and they sometimes dont have a buggy for you!). Also you play off the forward tees which means it basically pitch and putt.
Basically if you like challenging golf courses, i would not recommend the algarve. We played five courses there and none of them would measure to say Headfort New, Knightsbrook, Rathsallagh, Mount Wolseley even Glen of the downs....
I've also played in Spain and although similar, there seems to be alot more space for courses. I recently played a course called Finca Cortesin, its just opened in Estepona and was a fantastic course with plenty of space and hardly anyone on it. [broken link removed]
Its expensive at around 80 a round, but at least you know you are getting your moneys worth, I'd gladly pay extra for some exclusivity.
I also played torrequebrada (definitely not worth money) and a couple of courses near Mijas which were better value.
My advice would be to find somewhere near Marbella and get a car. As for specific packages, contact an agent on the costa
http://www.golfinspain.com/eng/
and haggle.
Good luck.