I swear I was /fine/ on a western saddle. That's because I was using a mixture of arm and leg strength. I get on from the right because I have issues and my right leg is stronger.
Though, seriously, he does project boats, and we're just mounting something to the side of the swingset, and it shouldn't be THAT big of a project. I have been doing squats, stuff with the ball, etc, but it's a lot different when I'm pulling my fat butt onto a 1000 pound animal.
So that's for the height. We were trying to make something to simulate the inability to grab that an English saddle eludes me with. Say maybe a foot just for something simple, for width, because I don't think it's that that's the problem I think it's actually getting me to swing up and over. But thanks for the armpit thing. I don't know how accurate it is considering I like my stirrups short, but I'll probably use a stool for a bit anyways. ^_^
I also like making things complicated. :P A lot of it is conditioning, and once I /can/ get on, just by doing it everyday will help my muscles.