Hi Jarve_el, you could try this link
http://www.sanahotels.com

We have used this group three times in the past, flights from Heathrow to Lisbon are about £150.00 and a taxi from the airport is about 15 euros ask before you get in as some will charge more if you don't ask.
We have had two weekend breaks in Lisbon both booked with Expedia on line and the best price we got was £189.00 for three days, not bad for a B A flight and a three star hotel.
http://www.expedia.co.uk
The best way to get around Lisbon is a travel card from Carris booth under the Elevador De Santa Justa on the Rua Aurea (rua do quro) this gives you travel on the Buses/Trams/Funiculars and the Elevators.
Hope this helps.
Dave

thanks Dave

can you remember which sana hotel you stayed in?

Hello Jarve_el, yes I can as we stayed in the same one twice in Lisbon, it was the Executive on the Avenida Conde de Valbom. It is right next to the one of the best Museums the (Calouste Gulbenkian) and the road has some nice restaurants just down from the hotel if you did not want to go to far at night, and just a short walk to the metro of Sao Sebastiao from here the city is just four stops away, if you need any more info let me know.
Dave

One more for Glynis,
Dave