Grasshopper lawnmower conversion

Hi All, I am working on converting a Grasshopper 725K from gas to electric. I have a friend that is helping me work on the wiring diagram and materials needed. We started by running a gas test to see how much gas was consumed at idle, driving, and driving & mowing. We determined it would be best to use two motors one to drive the hydrostat and one to run the PTO for the mower or snowblower.
I am using 15 Calb 180 amphr Lithium batteries. I am using a miniBMS system on the batteries and an ElCon charger. The motor for driving the hydrostat is a 48v 8.8 hp AMD bpo-4003. The motor for the PTO is a 48v 7.9 hp AMD. We are currently looking at using the Alltrax AXE4844 controllers for both motors. I feel the hydrostat does not need an adjustable controller, but not sure what to use otherwise. We will using a DC-DC converter as I have lights on the mower and blower that I may want to use.
Any thoughts or suggestions on this project?
Thanks, Paul

I’ve been wondering if you could use 2 electric motors in place of the hydrostat (one on each wheel) and 3 smaller electric motors for each of the blades. Would it then be possible to keep the gas engine to generate the electricity instead of going full electric and running on batteries? My idea is to eliminate as many moving parts (points of failure) as possible. What do you think?