Derek is a propulsion professional. He knows what it takes and what it costs. I think you really need to sit down and discuss with him about the budget required to conduct a campaign to send a rocket into space. You must be realistic and realize that if you can't figure out how to finance a project similar to Ky's GoFast which cost between $500,000 to $1,000,000, then it's a no-go before you start.
I suggest you go to the UP Aerospace website to see the typical minimum vehicle you need to reach space (100+ km).
https://www.upaerospace.com/custom-1/UPA PUG Lite R121214.pdf The 10" SpaceLoft XL(R) vehicle is the commercial equivalent of Ky's rocket, and was the vehicle Ky launched on the 10th anniversary of the 2004 event. I believe that CTI manufacturers the motor.
Other vehicle prototypes are the Super Loki and the Super Arcas launcher families. The 4.5" Super Loki booster has a short burn motor and loft a 1.5"-2" dart to 100 km with a very limited payload capability and the 4.5" Super Arcas uses a very long burn motor that is very hard to manufacture and operate due to severe thermal issues.
Bob