Gav, as we know 9 out of 10 6 cylinder BMWs are auto's rather than manuals for residual and everyday driving style.
I guess you could give an auto a test drive, wait for a manual 335i or look for a new unsold one or a new factory car with a good deal on it. I still think your current car looks stunning but understand the desire for a good spec 335i Sport with the 19's / NAV etc.