Aero Algarve at Portimao is run by a really good guy, Ken Thomsett, and it's pretty easy to hire aircraft from them.
Either ring on 00351964954279
or email
[email protected]
The only slight PITA is that you have to file a flightplan for each trip and, if you're used to something a bit more sophisticated, the banner-towing 172's can seem a bit, err, basic....