You can always buy a D helicopter kit from QCR. or get the plans from NARTS. D rotaroc aren't the much different then building a 13 or 18mm model.
By the way, Once you've built one you'll have the Plan for all the others. almost all of my HD models were built for the Contest plans packet from NARTs about $5.00 or so. the packet has all kinds of Helo's, gliders streamer, PD and egg lofters. Well worth the couple bucks.