Unfortunately, Rocha Brava is one of those locations that is somewhat isolated from access to public transport but also from the local community. If you want to explore the Algarve a hire car is recommended. Remember to specify automatic shift (which will atrract a premium) as most vehicles this side of the Pond are manual shift.
I would not normally recommend travelling to the Carvoeiro area from Lisbon, as public transport options are not good. The nearest public transport hub is Lagoa Bus Station or Portimão Rail Station. However, it is unlikely there will be enough taxis on service at either location to lift 11 people with bags. You would also have to get from Lisbon airport to either Lisbon Gare Oriente Bus/Rail Station or Lisbon Sete Rios Train Station.
Links to train timetables and the services offered by bus companies Rede Expressos/Eva and Renex are available in the panel entitled "Algarve & Portugal - Travel Transport Links" to be found on my blog here:
http://barlaventostravelblog.blogspot.com/
By toll motorway, the distance is 270km / 3 hours drive. A private transfer for this sort of distance will be quite expensive.
I do not understand why you are not flying into Faro Airport which is +- 70km from Carvoeiro and is the regional airport for the Algarve.
From there, it would be much easier and cheaper to arrange an airport transfer direct to Rocha Brava.
The following company is able to quote for such a trip:
http://www.low-cost-transfers.com/faro-airport/
Current prices are in the order of € 108.00. Thes may increase by next February however.
The same company is quoting a price, on their Lisbon Airport Site, in the order of € 520 from a similar transfer from Lisbon Airport to the Carvoeiro area.
