Hosting would be nice actually.

As for reliable multibox gear - you need to go hardware. It works. Period. Software.... sometimes does and sometimes does not.

It would be possible to refine Synergy/Multibox's code if you are so inclined.

But if you are serious about multiboxing - consider SOME kind of hardware route. I don't care which one but the Vetras I have used for 2+ years and they have never missed a keystroke. Ever. That says something to me.