Sounds like you have spent some time with this already.
This is feeling like a 4 grain , 75mm motor that is an M and not an L... The longburn M650 may start off gentle but will keep building velocity .. and end up going fairly fast before apogee. Use Thrustcurve with a mass estimate and look at the velocity and G of the flight as well as they predicted altitude.
Dont get to bogged down on the most ideal motor.. Motor availability, hw availability, $$$ , flying season may all influence your final selection more than anticipated.
Doing a test flight with a smaller punchy motor may alleviate some fears of the velocity and Gees your bird can take....also seeing the electronics work for a successful flight is always welcome.
Two of my rocket buddies went with the AT 1500G .. Punchy but on the lower side of Ns like the M1101..maybe not your ideal but may add to your short list
Kenny