Thanks Monkey. Did a little research and ended up with a bunch
2 - Kidde 9000 smoke alarms. Dual sensor like you said. http://www.amazon.com/gp/product/B00...ls_o01_s00_i00
2 - First Alert CO615 for CO detection low in the room. http://www.amazon.com/gp/product/B00...ls_o00_s00_i01
3 - First Alert CO410 for CO detection high in the room. http://www.amazon.com/gp/product/B00...ls_o00_s00_i00

I think that should be enough to cover my paranoid ass.