My one previous effort with a home built mid engined transaxle car was about thirty years ago with a Lotus Europa fitted with a rotary engine and Porsche 911 transaxle. The biggest difficulty with it was the well known problem of routing the gear linkages back around the engine.
Sourcing a transaxle robust enough for a V8 seems to be mainly a problem of money......
Another less neat way to go about all this would be to use a conventional manual gearbox fitted to the front of the V8 engine, and a locked up transfer case to transfer drive back along a prop shaft to an offset rear diff.
The advantages are that the gearbox is right under the gear lever, and don't underestimate the value of that. Plenty of super strong low cost SUV gearboxes that bolt straight up to your V8, and the engine accessories like the dip stick and fan belt are at the back where you can get at them, not buried behind the seats.
Many SUV gearboxes have "cousins" with close ratio gear sets, for example Toyota Supra gears would fit into a Toyota SUV gearbox, which is really the same box with just a different output shaft.
To make the whole thing go in the right direction, you need to have a "front" SUV reverse rotation diff mounted upside down.
The rear half of a Bugatti Veyron works something like this. Like an entire SUV turned back to front.
It could all be very easy to do at reasonable cost, with standard original parts that all bolt straight together.
And if the transmission will not break in a two ton SUV towing a huge boat trailer, your little mid engined sports car is not going to break it with a LOT more power.
It is a bit weird, but I am sure it would work.