Ive got a waterproof jacket that i got about 9 years ago, use it just to walk the dogs now as both the zips on the pockets broke.
sizes came up on the big size my XL is way too big for me and I'm a big chap... where as the GG XXL is just about right.
I don't thing you will go far wrong with Sunice. its also worth looking at Zero restriction which is the US version of GG. our pro shops stocks these and it was way cheaper than GG for the gortex, though they did have some trousers that were £300!!!