Like Neil said there are a lot of good chairs to choose from and the one Neil mentions is a very good make depends how light you actually want it.
I my self went for a Helium Generation 2013 by Sunrise Medical, had one of their guys to come with one to test drive. And to measure me up for it. I put the empathise on the weight of the chair and mine is 6.2kg and then when folded with the quick release wheels off to put in the car is 4.2kg which I can lift above my head. It seems well made some sort of carbon fibre material they use. very strong.
Its not cheap unless you can get some help but well worth it, its my wife who has to fold it up and lift in the car which she finds easy to do, No strain on the back.
Let us know how you get on.