Ritmo was called 'Strada' in uk and had up to 130bhp in Abarth guise. Not sure if they ever marketed it stateside though.
X1-9 initially used 1300cc motor and 4 speed 'box from Fiat 128 Sport/Coupe/3p Berlinetta. Only 75bhp but a lovely, free revving SOHC engine that came on cam at about 3000 and pulled
hard to 7500rpm (way above red line) without breaking a sweat, or breaking. My 3p could keep pace with 2 litre Capris and Cortinas back in the day and outhandled just about everything on the road at the time (Peugeot bought the innovative passive rear steer suspension setup Fiat used on the 128 and put it to good use in the 306).
The later incarnation X1-9 had a five speed 'box and 85bhp from 1500cc's, and I've always wondered if the 1.4 from the Uno and Punto Turbo ie models would bolt straight up to the gearbox. With 115bhp and loads of torque from its water cooled turbo, that motor would be very interesting in a lightweight road racer.
Failing that, Honda have made some cracking front-drive cars over the years that sold well in the states and could donate their mechanicals for not many pennies (or cents).
I'm sure a suitable drivetrain will present itself sooner or later.