I am 5'9" and have a 29" inseam. Dropped the front 1" originally with reaper 1" risers (slid the forks back up to the top clamp cover, but now I have an aftermarket that they can slide through.
Going down 1" in front and buying a TOBIN seat that takes away a bunch of seat material (but is still comfy) was enough for me to be on firm balls of my feet...can't quite touch down both heels when at a stop. However I can lean slightly to one side and have one flat.
However keep in mind that all you need to be concerned with when lowering is getting it low enough to get the balls of your feet on the ground so you don't tip over at a stop. Getting flat footed shouldn't be the point. Balls of your feet are just as good at everything except maybe backing the bike up, however I can manage fine...