I am 5'8" and would love to find a option to lower my 2012 SESG about an inch. I still would like to keep the same ride and need the option to be safe with the least cost possible. Primary objective is not improving the looks as much as improving my stability at stops.
Your bike is already lowered an inch in the rear compared to an Ultra. Lowering it any more will definitely not help ride comfort, as shorter shocks have less available travel and tend to be harsher. Lowering it further will also affect handling and ground clearance to various hard parts.
I am also 5'8" tall and my bike is lowered 1" from the factory. I solved the foot traction and stability issue with a good pair of riding boots that have a thick high traction sole and heel. That is the least expensive fix I can imagine. Next, if you need more than what just boots can do, get your seat modified to lower you and let you keep your legs closer to the bike (narrow the nose of the seat), or just find a better aftermarket seat that will do the same thing.
Jerry