Measurements for custom Guffy saddle

My friend and I have been looking for new saddles for a while and have been recomended to buy Guffy saddles by many people. We've been told they are the best for the money, and we can get them costum made for under $600. I know that I need a wide tree, a decent curve to the bars, round skirt, and I want a deep seat. Where EXACTLY/how exactly do I measure my mare so I can get a saddle that fits her perfect? I've always had my horses fitted at the local tack shop and bought from there, but I've been waiting since December and they just aren't getting enough used saddles in. The tack shop owner doesn't like the lady who orders the Guffey's, so I can't get her to measure for me. Any info on Guffeys and flex tree vs. wood tree as well?

One of my friends and my sister both had Guffy barrel saddles..They wore okay and will last a while but to me they were really comfortable and the color from the seat will fade onto your pants for a few rides..I'm just not a fan.. If you want to email Sierra about her saddle I'll be happy to give you her email in a PM. My sister gave hers up and bought a KO barrel saddle.

My custom KO cost me $800 and I've been riding in it for 3 years now, I love it and I've never had to replace anything on it. I'll definitely order from them again when I want a new saddle..