I didnt read through this entire thread, but the first thing that came to my mind was the deadbolt I have listed in the classifieds
http://www.cocoontech.com/forums/index.php?showtopic=17736&st=0&p=147703&hl=lockstate&fromsearch=1&#entry147703
It is motorized, and comes with an IR remote/keyfob so you dont necessarily have to enter the code. I am certain there are other options available if you dont like the design, color, etc.