Is this setup possible?

I'm trying to add a semi-secure public WLAN to my existing network, which is pretty complicated. I have little experience.

I have been doing some research about NAT and networking in general, and I have come up with this schematic. I don't know if this setup is even possible with the equipment we have, or at all. I need to know what is needed to set this up, what type of cables (crossover, straight-thru, etc.) are needed, subnet settings, etc. if possible.

This network, sans the devices listed as "not having", is already setup and working.

Of course the current layout is a little different towards the top.

I want to have multiple NAT routers so that I can have a semi-secure public network and an "ultra" secure private network.

Thank you very much.