GL-Inet.com creates nice clones of TP-Link WR-703 routers. They run OpenWRT out of the box, and have 2 ethernet interfaces, a 2.4Ghz Wifi (802.11n) radio, a usb2.0 port and 5 free GPIO ports.
The device runs OpenWRT out of the box, but it's quite easy to build your own image. Currently revspace has 1 GL-inet 16MB device, and an order has been made for a batch of 20, which should arrive somewhere around the end of April 2014.
It might be interesting to host a local build-environment for the GL-Inet, as building a custom build means you can't use the normal repositories for kernel-packages.