Stock build purchased built & used off Ebay...will modify.  Of note is that I had built one of my own a year ago, but forgot to attach the clear fins (too many rockets grabbed that day).  No fins was a big mistake, but resulted in a hilarious flight as R2 swirled around the pad, crashed head first into snow and then did a firey explosive discharge from his butt...even the chute and lines were on fire for a bit!  Has been repaired and will fly again, but first I'll modify this used one since it's already beat up and I can do more testing on it.  

*UPDATE* - Modified with small kevlar anchor cord and 1/4" x 36" Estes shock cord and finally got a successful flight.