All,
As per tyres and stuff its down to personnel preference, however, for my Green laning during the winter and my Quad racing days I have always used and would recommend Lindstrand gear, the Graffiti range being the top of range - waterprrof, windproof and in my own opinion keeps you warm warm warm....
http://www.adrenalinatv.co.uk/product/?pid=4661
Have a look on the Adrenalin ATV website link above, the jacket is around �200 and the trousers around �190, but all in all, as the Capt states, you get what you pay for.
For the uneducated around Lindstrand, they have made Ski/Snow gear for 20+ years for Norway/Sweden etc etc, where the winters are much colder than in the UK, so they are certainly tried and tested.
But, it's all down to personnel preference. If i had the dosh i would buy Hein Gericke all day long, but i felt that the Lindstrnad was a close 2nd at hlaf the price of the HG stuff.
Cheers
WB