Sorry I don't know zipper lengths, but just thought i'd add that armada outerwear is fantastic, I have pants from them, no rips, stains, or any other form of molecular decay and if they weren't an inanimate object I would probably have sex with them.
So I had the old down jacket that they used to make (I assume they are similar). I got it in 2xl and I'm 5'8". It was pretty big, and I'd buy a 2xl if you want it to be big. My zipper was 32" and went like 6" from my knee. It was pretty much the fit I was going for but it fits big and tall so keep that in mind.
armada is very wide. that is the only complaint i can have about them. i love my set up i have a large spectrum jacket and it is very nice. just keep in mind that when you go bigger it will get much wider
They have some stuff that is tall fit and some stuff that is normal fit. The tall fit is about 3 inches longer than the normal. I think my normal fit xl is 33 or 34 inches.