You're going for footie, aren't you!!!!!
FC Porto vs Manu U.??????
A Minibus would probably be cheaper but as your average mini-bus will only legally carry 8/9 persons, it may be expensive.
I also do not think it would be worth the risk hiring a 9 seater and trying to get away with 10 on board as the Portuguese Police will be out en-masse in Porto and on the approaches to the city.
Your real problem is that you need to get back to Lisbon by 08:00 on the morning of 16th April.
The nearest train station to the airport is Gare Oriente where there is also a bus station. You would need to take cabs to and from the airport. About 10 minutes. The last train departs for Porto at 21:39 arriving at 00:39.
There is a regional train taking 4 hours that leaves Porto - Campanha at 1h23 and arrive Lisbon - Oriente (10 minutes by cab from the Airport) at 5h42. Problem is you can't buy tickets in advance.
Train timetables here: http://www.cp.pt
www.renex.pt have a bus service leaving Porto at 01:15 and arriving Lisbon - Gare Oriente Bus Station at 06:00. Again you can't buy tickets in advance.
The following transfer company is quoting € 960.00 for the service you require for 10 persons return.
http://www.low-cost-transfers.com/lisbon-airport/index.php?goloc=51&transfer=Porto
The advantage of such a service is that they provide a driver and you don't have to worry about parking, drinking etc.
