I owned a couple of British built Royal Enfields back in the 1970's, I bought a gokart from a guy which was fitted with a RE 500cc engine and gearbox fitted, with a Holden (Aussie GM) carb fitted. It wouldn't idle below around 1500 RPM, but would do 105 MPH. He had some friends follow him one night in their car to see how fast it would go, the only problem (and why he sold it to me) is that it had massive understeer, and didn't like going around corners at speed.
I took the engine out and fitted it into a 350 frame, and "Fonzie-fied" it, and it was a cool cruiser, for sure. I joined the army and my folks moved house, so gave all my RE stuff away, but they were a good solid bike, not fancy, just good working class iron. I'd have a Continental GT, but I'm 6'4" tall, and probably weigh more than the bike, so it's not a good look.
That T3 would be my choice. My mate Pete had one for years and I rode it a lot, the square slide carbs are sh1t, but fit a set of 38mm Dellorto round slide pumpers and a set of "Doctor John" pipes, and unleash the beast! They handle really well (way better than any Jap bike of the era) and same for their Brembo brakes, brilliant! Cheers, Terry.