Well, I won't be of much help to you, as I'm 5'8" with a 32" inseam. I have a '95 ZX6R, which I'm not just flat-footed on, but my knees are slightly bent. I can flat-foot or nearly flat foot on MOST bikes (I think the KTM Super Duke is about the only one that feels unstable to me/that I can't get good footing on).
There's a thread in this forum on seat heights of most major manufacturer's bikes. More important than your overall height is going to be your inseam length... if you're of average height, but have a very long torso, then you're going to have less clearance than someone who's maybe shorter but has very long legs.
Many bikes can be lowered, though there's much debate as to whether or not this is safe. I'm of the opinion that bikes shouldn't be lowered as it compromises the handling. Bikes are engineered to perform optimally at their stock height, so when you alter the height, you're changing how it performs.
That said, there are "right" and "wrong" ways to go about lowering a bike. If it's done properly (and done the same amount front and back, i.e. if you drop it 1.5" in the rear, do the same in the front), you MIGHT not notice too much of a difference (but that's going to depend on the bike).
Another way to get some height is to get women's specific riding boots with some heel height. SIDI makes several styles of high quality, supportive, safe riding boots that can give you up to 2" in height. They'll have the ankle reinforcement and oil resistant sole that other riding boots will have, so you won't sacrifice safety. I do NOT recommend boots like the Icon Bombshell boots for riding. They're :drool hot, but they're truly not any safer than any fashion boots when it comes to riding (no matter WHAT Icon contends