My certification flight is between 15-20k depends on motor and simulation accuracy. I’m planning on flying it after the cert flight on a large M then a small N then a full N and lastly the disposable O from Aerotech. This is all on the assumption that nothing goes wrong as I work upwards in impulse.
You will be fine using just about anything. UNLESS you are at a field 5-8,000ft above sea level.
It can get wonky above 20-22k depending on where you fly, although I have flown to 24,500 with charges in finger glove tips. [Chicago area]