Step-through frames with longest effective top tube?
 

I'm about ready to buy a new bike for my wife. Main use is daily commuting. She needs a step through frame because she often rides in a skirt. She is long legged but also fairly long in the torso. Her current bike, which she has gamely ridden for almost ten years now, is just tall enough for her legs but pretty cramped front to back. I've been researching frame geometries of every step-through hybrid I can find. It seems that the REI Co-op CTY 1.1 has the best geometry, but it still seems a little short in terms of cockpit/top tube/reach, and the listed stand over height is pretty high.

Here's what I've found:

Bike / seat tube / effective top tube / standover /reach
CTY 1.1 step thru / 425 / 580 / 719 / 404
Fuji Absolute 1.7 ST / 432 / 539 / 681 / 389
current bike / 500 / 520 / 580 / 380

Just thought I would check and see if I'm overlooking any models.

Maybe you should compare the frames in terms of stack and reach. Effective top tube will also depend on the seat tube angle. Also, if you build from a frame you can add some spacers above the headtube. This way for every 1cm of increase in stack the reach decreases by 1/3 cm (tan 70 deg is approximately 3).