Hybrid motors are available to those without a high power rocketry certification. Look at SkyRipper Ssytems and their 29mm motors that have 2 loads for them in the G motor range.
Only requirement is that you be 16 (18 in some states) to purchase the nitrous oxide. I don't think the explosion that happened was due to a hybrid as much as it was that they were loading liquid nitrous in 99 degree F from a large (3000 pound) tank to the smaller, flight tank. If they were not careful and kept the tanks cooled to below 97 degrees F (critical temp for nitrous) then they would never have transferred any liquid nitrous, only gaseous nitrous. If they were measuring the fill rate by weight and not pressure in that situation, they could have over-pressurized the flight tank which would rupture and send shrapnel for 100's of feet in all directions.
My thoughts go out to all those involved.-Aaron