I like your choice of colour.
However, you may have to wait quite a long time (or pay a high price) for 5k mileage.
They've been fairly rare recently, and cost £1-2k more than one at 8k miles, which seemed to be the sweet-ish spot last year.
However, if you're set on 5k, I reckon your best bet is ask a BMW dealer to keep an eye out. They may have some coming in for part-ex that you could have first dibs on before they get advertised. Cost might be higher but you'll get 24 months warranty thrown in (~£600-700 worth). Steve (slparry) could be v useful here.