Need advise on components

I am currently building a 1969 cj5 from the ground up.

The drive train consist of a 3.7 225 ICE, a t-18 low ratio 4 speed(6.32, 3.09, 1.69, 1.0, R7.44)mated to a dana 18 transfer case(2.03,1.0) running to Toyota land cruiser axles that have 4.11 gears. I plan on running 35" tires.

The cj-5 without the any engine/batteries weighs 2400 lbs. So I am guessing a weight of 3200 lbs using the hybrid system.

Been going back and forth between the 3.7 liter 225 ICE engine that gets 15-22 mpg(using optional overdrive that would cost me $1000 in the dana 18 giving me a 5th gear of 0.75).

Or using a electric motor running a 96 volt system. I can comfortably mount 6 batteries under the driver/passenger on the outside of the frame rails and 2 in the area between the tub and the front wheel. I would also mount 2 batteries for running the 12/14 v system on the frame rails towards the front.This would give me a low cog while giving a clean look. All these batteries would sit inside uhmw hdpe(cutting board plastic) sealed boxes.
Using this small of a system I would want to make a hybrid.

I was considering using a liquid cooled 2 stroke(reliable/very few moving parts) 250 cc (motorcycle) engine. This would not only power the generator but also power the power steering pump, the alternator, provide heat(using the liquid cooled radiators as heater cores), provide vacuum(for the 8"double booster) while keeping the engine bay generally “clean” looking.

The 250 cc motor would mount normally next to the grill on the drivers side. I could run a 2 belt system having the accessories running next to the electric engine and a direct drive(via a shaft) off of the motor leaving the generator mounted sideways directly behind the grill.

All of the components are above the frame rails and would be enclosed (except the 250cc motor) in a 3/4" sealed acrylic box with dual fans towards the firewall pushing the air out towards the windshield.

The 250 cc motor would run around half throttle(3000 rpm) from start to finish and continue running to charge the system while parked.

I want a couple things from this system.

–I want a range of 150 miles non stop running 75 mph on the highway having a average speed of 55 mph. Remember it is a hybrid and the generator will be running during the entire drive time.

–This will be used off road(hence the acrylic box).

–I will mount as much controllers mounted above/between the driver/passenger (on the roll cage ceiling). This would not only keep them from getting damaged by the elements. But would provide easy access and better cooling them putting them inside the acrylic box next to the electric motor.

-I want to use a 96 volt system

–I want to use yellow top optima batteries or some form of dry cell that is ok running on its side.

–I want to see practical mileage of 50-60 mpg

–I want a meter that would shut off the 250cc engine once the battery pack reached peak charge. So, I could park it and forget it.
A 15 gal tank mounted on the passenger side of the engine bay (making the engine gravity fed so no need for a fuel pump) would provide a good amount of run time for the motor to charge the battery pack.

-I would like to spend no more then $8000 on the motor/controllers and generator. It sounds like a lot but from what I have seen I am looking at 6k easy.

What I would like to know is what is the best components to use to make this happen.

Been testing the waters on this for a few years. But, not totally ready to jump in without some good advise.

Thank you