These were mentioned on the ATT newsgroup, and look pretty good.

Custom Rodimus (from Cyb Megatron toy)
http://cgi.ebay.com/ws/eBayISAPI.dll...m=110280695481

Poseable Custom Devastator (from Micromaster Constructicons)
http://cgi.ebay.com/ws/eBayISAPI.dll...m=120293983988