-
We went sliding for ours - bi-folds just seem too prone to breakage unless you go for the expensive ones, French doors are fine if that's the style you like but I guess you'd want a large patio to open them into so wasn't suitable for ours.
We got our doors from 1st Sliding Doors - they were pretty good to deal with. I assume they're just a reseller rather than a manufacturer but who knows? The glass comes from someone else anyway.
Velfac/Rationel