KVM-type switches for with HDMI & working USB?

I have two PCs and I'm hoping to clear some desk space (and increase functionality) without breaking the bank.

I'd like to be able to do the following:

PC1, LCD monitor1(HDMI). Currently running Vista32, although I may go to Vista64
PC2, LCD monitor2(VGA). Running XP
with a ps2 keyboard and USB laser mouse that switches between the two

...ok so far that seems normal... but I also want to be able to separately switch LCD monitor2 to become a secondary monitor for PC1 (which has a dual HDMI video card) when PC2 is off (and of course, the keyboard and mouse defaulting to PC1). Both monitors are HansG 194D with both VGA and HDMI inputs, although I don't know yet if they can switch themselves (solves one of my problems) or if they only accept one live input at a time.

This will only work for me if I can switch the keyboard and mouse (and monitor) on the fly without rebooting and not have either machine lock up.

Any suggestions? Last time I looked, it seemed like there were no switchboxes that could reliably handle USB mice (and potentially, keyboards) on the fly, and I have no idea about the video, especially if it would be on a separate switch and switch from a VGA to an HDMI output.

Thanks for any advice,
Keith