I agree with NJDude as well. Code your app to scale for any size, and you'll never have to worry about variants. It's not hard, and after doing it a couple of time, it will become second nature.
I come from a Windows/Linux background, and for me, the entire thing with variant layouts just seems unnecessary. I've never made different form variants for Windows to accommodate for the user resizing the window, instead, I just scale the contents intelligently.
Example:
Say that I'm doing a typical web browser window, with some buttons top left, then URL text box and then the web page below and a status bar at the bottom. It's trivial to write something like:
buttonBack.Left=0%x 'Put button at far left
buttonForward.Left=buttonBack.Right 'Put button next to previous button
buttonRefresh.Left=buttonForward.Right 'Put button next to previous button
textURL.SetLeftAndRight(buttonRefresh.Right, 100%x) 'Let the URL textbox span the rest of the width
panStatus.SetLeftAndRight(0%x, 100%x) 'Set status panel to span full width
panStatus.SetTopAndBottom(100%y-panStatus.Height, 100%y) 'Put it at the bottom of the screen, while preserving height
web.SetLeftAndRight(0%x, 100%x) 'Span full width
web.SetTopAndBottom(buttonBack.Bottom, panStatus.Top) 'Fill the available height between buttons and status bar
This way, it will resize intelligently. Sure, some cases are a bit more complex, but it's seldom difficult.