I have a SoHo network and I want to make it ultra secure for business related intellectual property.
My idea is to take a dual Ethernet single board computer/embedded micro-controller and install it as a bridge inline between my modem and router with a proxy that only allows whitelisted internet domains.
I've looked at these projects: openwrt.org, zeroshell.org, and whitetrash.sourceforge.net. A stripped down distribution like Debian is also an option.
I've also looked at a few SBC's listed on zeroshell. What I'd like is to have an OS installed to the SBC's flash, and then the database/swap area mapped to a SD card. Even better would be able to toggle or solder/burn the write enable on the SBC flash; thus no way of compromising the stored OS.