Looking for quality KVM switch w/ video for two systems

I am trying to locate a high quality KVM switch of some kind that will allow me to plug both my PC tower and MacBook Pro into my mouse, keyboard, USB speakers, and dual-screens, and allow me to switch between the two systems.

I am also looking for one with minimal input lag, as I do use my PC for gaming. My budget is around the $100 to $150 dollar range. I have two screens, one is a 20-inch Asus monitor connected via DVI-I (also has a VGA port) it has no modern connections (HDMI, DisplayPort, etc.).

My main screen is a Dell U2515H, it has HDMI, DisplayPort etc. I currently have it connected to my PC tower via DisplayPort, and the Asus connected via DVI. I would like a KVM switch that allows me to plug in these two monitors and at least 4 USB devices so that I can switch easily between my Mac and my PC. Problem is, I don't know if such a device with my specific needs even exits :/

Any and all suggestions are welcome, and I thank you in advance :)

Have you looked into Synergy (software based solution). I am not sure what its like for latency (I believe its perfect for normal use but not sure about low latency gaming) but from what I've heard, it is meant to be very competitive, if not better than traditional hardware KVMs.

Its a one time payment of $19 but I'm sure you could find a way to test it first.

As a side note, I didn't realise Synergy would included the LTT video that they did for this on their site.