Hi Monica: To be honest I'm not sure what size of harness we ended up with. We sent measurements to a company in BC and we still ended up sending pieces of it back to exchange for a different size. For one thing, Gusti needed a draft sized crupper. What ever you buy, make sure the saddle pack has a good spine channel and is well padded.
If I had to guess at a size I would say Gusti would be closer to a cob size, though he has a full sized bridle. He's a tank. So far Gusti has only pulled a travois, but we intend to work him up to a stone boat this winter. I'm presently taking a few lessons on him until the snow flies. Wanda