yes a 80cm dish is the right size. A tripod/pole, with
adjustable legs and a spirit level,that can be attached to the ground with a 'corkscrew' fixing would be a good idea due to the wind factor. i would also reccomend using a Sky box rather than any other make as the inbuilt stellite meter will help in the setting up along with a 'satbeeper' to actually find the satellite. a compass is essential, after a few goes i am sure it will become easier. a reasonable length of cable would be a good idea so the dish can be placed outside the shading affect of any trees etc. BTW the dish points at Astra2 approx 28.2 degrees East of South with an elevation of 34 degrees (here)
I hope this helps and would be happy to offer any further advice.
The Skyman
www.british-tv-in-france.co.uk