Actually, I would like to build something like this from my one of my many parts Samurais. Not for economics, but for a cool street cruiser-a safer motorcycle.
Last year I picked up a 2wd Samurai beam axle. It is actually offset to lower the front end about 1/2". I was thinking of lowering the Samurai even more by "frenching" in the spring mounts though.
For the engine and transmission, I would use a 1.6 and 1.6 manual tranny. I would also convert the rear end to a trackick rear end so that the pumkin is centered. Might even swap over the trackick rear coil suspension over too. I've also considered swapping in a RX7 Rotary, but it really doesn't make that much power (the carbed versions) over the 1.6 Suzuki engine which is bolt-in.
Of course, I would ditch the doors, targa bar etc, and might even go without a windshield (front cage though). It would be kind of like a lowered VW Thing or WWII era Kubelwagon. I would paint it gray or dark green and put a big red dot on the hood-a Suzuki Zero! Of course, I would drive it around with a leather flight cap, googles, and jacket.