Western saddle were not made to fit horses like that . If you're not showing, you might think about an Aussie saddle with padded panels. Be careful with cheap Aussies though, you get what you pay for .
My tb looks almost exactly like Erin's. I am using a saddle with full QH bars like you said, and having to use several pads to keep it off his withers. I am looking to buy a new saddle, and I really like the wade saddles. I'll keep looking.