I was in the neighborhood with the voltage then. You'd be looking at a nominal 104.4v, or a 29sXp pack. Depending on cell size will give us the required "p" stack number. You'd be looking at a custom pack, plus BMS and charger. Seemingly simple enough.
The pros of the zero pack: very well tested, great information out there, very safe. The weight is nice, but could be lower without their proprietary case.
Pros of a custom pack: getting the kWh you need, and building in safety percentages. Getting the lighter weight. Ability to run any type of connection to the motor controller, meaning flexible mounting options.. Most likely, a lower start up cost. The zero packs are almost $3000 each plus a $600 charger. Which the charger price is actually pretty decent. In aviation, I'm sure this point on price is the least weighted for a decision, though.