Ulrik's apartment is perfect for a single person, and has everything you need for a stay in beautiful Lisbon. It's located along the line of the 28 tram, but unless you absolutely love being stuck with other tourists in a limited space, I suggest you walk to the center rather than jump on the tram. It will only take you 10-15 minutes anyway.
Although I never met Ulrik in person, he was quick to respond to messages and made me feel welcome.