[Mike]

If the 06 ST3s has the same adjustable linkage as the ST4s lowering the ride height would be a simple adjustment with no money spent. I'am sure that the forks can be raised in the triple clamps as well.

Lowering the rear ride height will completely ruin the fine handling. If anything, it has to be raised a bit to get that delicious balanced feeling. If you lower the front to compensate then you will reduce cornering clearance, unacceptably IMO unless you never get the bike leaned over far enough to matter to begin with.

A custom seat can go a long ways towards getting more ground reach but I would suggest that good slow speed riding/parking technique and a little bit of situational awareness completely eliminates the perceived need to get both feet flat on the ground.