I'm finishing up a personal project PCB design, and decided to throw it out for input before I finished. I'll be publishing all of the files when I have a revision that I am happy with. I actually built this design already using Imp003, and had the first rev of PCBs manufactured by Seeed Studio. Unfortunately, the quality of boards that they make is just not sufficient for Imp003. The PCBs are not perfectly flat, and the radio power enable pin frequently doesn't make contact. I've seen this issue on higher quality boards as well, but Seeed's boards are only good for designs that need lower tolerance. I've had good luck with Gold Phoenix.
This design is intended to control all of the LED strip lights on the market. Neopixels, DotStars, standard 12V RGB strips, ect. If you power it with 5V it will level shift a CLK and MOSI line, and if you power it with 12V it has three PWM outputs for RBG strip lights.
In addition it will have two inputs for buttons, PIR sensors or other triggers, so you can complete this project with an Imp if you aren't an Arduino fan. http://www.instructables.com/id/LED-Stair-Lighting/
I'll also be breaking out the wake pin, and a few others depending on how many header slots are available.
The PCB is designed for this enclosure, which will need to be milled for the power jack and any cables. Alternately, a custom top could be 3D printed. https://www.newageenclosures.com/enclosures/utility--desktop/network-cube.php
If anyone has other good ideas for related functionality, please comment.