I'm wanting to do a staged HPR build. I'm not opposed to scratch building, but I was wondering if there are kits out there that people like and recommend. Always nice to know what the options are. I'm thinking 38mm, maybe with a 54mm booster. Mostly because I already have the hardware I would need for the flights. I'll use a CTI motor for the upper stage to keep ignition easy. Probably AT for the booster unless I decide to go nuts and use a Skyripper.