The dirty little secret is there aren't that many manufacturers of officiating pants. You might give the Gerry Davis pants a try as they have the adjustable waist clamps that allow you to take up/let out. I had a pair but gave them to a new official last season.
These pants are mass produced for the greatest number of men so if you need special tailoring, you're just going to have to have it done.
The original Gore-Tex officials shirts ran about $200 or so, which is why you can't find Gore-Tex shirts now.
I bought one of these from the former Honig's dealer in the Northeast. He's marked them down about $15. Its a coated pullover jacket basically. It isn't Gore-Tex but its about the best you are going to find.
SOLD OUT WHEN GONE Hong's 2'' Stripe Windshirt - AllSports East