I’m 6 foot, and I have a 32″ inseam.
Don’t discount the Ninja 250/500 or GS500. They are “standards”, throw a set of soft luggage ($100-$200 bucks for a set) over the back seat and you can hold stuff for a multi-day trip. They are also pretty darned comfortable on the highways.
I find the dual sports to be far less comfortable (norrow hard seat), and have a more limited range between fillups (2gal tanks vs 4 gal tank on the street bikes). They are equally capable of carrying gear (still need soft luggage, or spend $$$ on a hard luggage set – I’d recommend saving that investment for your second bike).
What consitutes freeway speeds to you?
Some of the 250cc dual sports are gears so they top out 65-70mph. I consider that fast enough for the freeways (around here no speed limit is higher than 60mph), but I know some people who consider 80mph to be the minimum for “freeway capable”.
The DRZ-400 can do 80mph all day and is a great bike if you find it comfortable.
Unfortunately the 400cc class is pretty much dead in North America.
As always, sit on as many bikes as possible, find the ones that speak to you and make the compromises you feel best with (alas, all bikes are compromises, but that is part of what makes each oen special).