Hi Andrew,
Myself, Mike and Andrew Durick used to compile a monthly observing challenge list a couple of years ago. Whilst none of the objects were difficult targets we would select one object of each type each month as the observing challenge. While the concept was great, it was very time consuming for the small amount of interest that was generated.
I hope you can arouse enough interest to make it worth your time and effort. Here are some links to the older files that we prepared a couple of years ago.
http://www.iceinspace.com.au/moc.html
Cheers,
John B