1 Network, 2 Routers, 2 (seperate ISP's), + open wireless

Hi guys,

I have been browsing the internet for hours looking for a great solution that makes sense. This is what Im trying to do. This is a small office network.

I have four PC's. Two on one router, and two on the another. I want the internet to stay split (2 on one, 2 on the other) but merge the networks so they can see each other for file sharing, as firing the data via a VPN is just a waste because it goes out the ISP through the internet and back in, when they are physically in the same building. Also there are wireless devices constantly entering the building that need DHCP access so shutting off DHCP is not an option unless I want to manually configure every wireless device that comes in. Wireless is off on one of the routers currently.

I know there has to be a way to do this, Im just looking for the answer as to the way to go about getting it done. I found some data out there relating to this but it was confusing to follow the conversation because they were skipping around.


Thanks to anyone who can provide some input.