Tim, nice work on your machines. Projects like that take some work. You're the first person I've seen so far making or extensively modifying a boring machine. I just purchased a Boss boring machine head on ebay and should receive it in about a week.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=170453636572&ssPageName=STRK:MEWNX:IT
I'll either have to come across a frame for it or make my own.