Not to mention that, unless you have a fetish for non turbo RB engines (if so. get help), a turbo car with non tubro engine is still a turbo car as far as the laws is concerned. So yes, keep looking for a non turbo one.
That being said, if you found a non turbo car that had been converted to a turbo one, you could legally remove the turbo and put normal minfolds back on and drive it legall, as far as i can tell.