time to upgrade from a Suzuki s40

I have been riding for a few months. I have a 2007 Suzuki Boulevard s40 which has been great to learn on. I'm looking to upgrade to something that can handle highway speeds, 75-80. I do not necessarily need to go to a big bike just something with better suspension slightly better motor. I average about 70 miles per day.

Any suggestions? I live in Michigan.