Stay 3-4 days at Duplex do Pipas and you´ll feel like you´re living in Lisbon. The location is quiet, still filled with stores & restaurants (some little gems hidden there) and walking to downtown Lisbon will take you 25 min. along beautiful neighboorhoods. Ah, you can always come back by the river, another fantastic walk.
Pipas is a great guy that will look after you while you´re there. Don´t worry about that.