Apologies for treading on the toes of the Nikon fan-boys in here but have you looked at the Alpha700 If you've already got an Alpha camera. It's not as good in specification as the D300 but if it's noise you're worried about it should be a cut above you're A350 because it's a CMOS sensor as opposed to a CCD.
A lot will depend on how much you've invested in the Alpha system already and how worried you are about getting a duff one, but it's something to consider.
Keeping the A350 etc as a backup and also for my son who's really getting into photography.So its not that I will loose moneywise.Thanks for the input I can see you have a valid point.