Instead of raising the seat, how about getting thicker seat foam... Sort of like an overstuffed chair. Of course, it would mean getting some custom leather work done to do the seat re-covering. You should be able to get a couple of additional inches in height .
I don't know that you or anyone will like a RAISED seat. If passenger space is not a major priority it is usually better to have a custom seat made that positions you back on the bike instead of up. This does not change the other ergonomics nearly as much as a raised seat. Worse comes to worse forget a riders backrest when riding two up as you gain a couple of inches back.
Generally you could say the bike is about right for a normally proportioned 6' fellow, perhaps requiring a slight pullback on the bars.
A couple of inches back in the seat and highway pegs should make it about right. The new brake pedal helps and the floorboards let you use different positions for your feet. A few of the people I ride with are that size and the bike is actually closer to right then you think.