Personally I think 17's may be too big, depends how low your looking at going?
Theres loads of various porshce wheels, Cookie Cutters (mine) Teledials, D90's.
alot of the older porsches (944, 928 etc) had the smaller wheels (15")
You've also got to think about wheels rubbing due to offsets etc, dont forget the spacers are about 30mm thick!
get yourself on clubpolo mate, all the polo boys use these adapters as polos are 4x100 aswell. you will need the centers bored out to 60.1mm to fit the clio.
any engineers can do this I paid £20 to have mine done.
and yeah that was my car. miss it masivley, also had 944 porshce seats in it too!