Try here for 16'' alloys :-
http://www.ebay.co.uk/itm/4X-LEXUS-220-250-16INCH-ALLOYS-WTH-MICHELIN-TYRES-/260859988907?pt=UK_CarParts_Acc_Wheels_tyres_Rims_Car_Wheels_ET&hash=item3cbc778bab
I have just bought some 205/55R16 Goodyears from Black Circles for these wheels, would prob cost you about £600 all in !!