[ProDarwin]

I'm late to the thread, maybe I'll have more time to contribute later but:

A) I am a mechanical engineer, I'd be happy to lend Design/Modeling/Drafting/FEA services.

B) Regard a vehicle for an AWD hybrid... choosing something that has a longitudinal mounted motor is a poor choice as you have the drive losses of the 90deg bevel gearset. This would eliminate Subarus, S10, etc. Something that is FWD based would be a better start as the FWD engine/trans could be left intact, while AWD rear components could be sourced/modified.

A Honda Civic can be converted to AWD through some fab and use of CRV rear components connected to the electric motor for example. Or just start with a CRV. Many FWD SUV Crossovers are like this (and this is exactly how the RX400h works - ICE front, EV rear).

Also when connecting to the rear diff , it would be worthwhile to machine a straight/helical gear to replace the bevel ring gear on the diff. This would again eliminate the 90deg turn in the driveline which is a significant loss contributor.

My gut feeling is the easy button is a FWD crossover, or a Civic/Integra with CRV parts out back. Getting further into home-fab, you could simply make a frame to mount a Miata crossmember under the back of almost any fwd car. Not sure how much $$ you want to spend on a donor vehicle.

Edit:

C) HP calcs are easy. Make sure you take into account grade-ability. I can help with this if necessary. I have spreadsheets for this, and also spreadsheets for simulating all of the drive-cycles, provided you have a BSFC chart for the ICE.