So, to summarize... you're looking for a cat that is as active as a bengal, will play with and tire out your bengal, but isn't inquisitive or adventurous and can safely be let outside free to roam without danger, won't put any further demands on your time, and won't take up any space in your flat?
I'm thinking those robotic kitties with the... no wait, those haven't been invented yet. Uh, I dunno, I got nothing. Maybe you could get a roomba?
...or you could just get a second bengal and live with the inevitable drawbacks