thanks for the responses.
Struggled to find anything via local breakers' yards and, given time restraints as I need to have my MOT retest, I've gone the budget alloys/tyres route via Halfords - £349.99 all in. Bit 'prettier' than I'd intended, but I'll cope. ;)
Hoping to sell the usable wheels on eBay to recoup some of the costs. Two of the weels have some pot-hole damage but not MOT failure damage; the other two have actually buckled slightly, enough that they're not repairable according to the place I took them to locally. Three of the four tyres are ok.
Was planning on selling my KA but, given the latest spend on it, looks like I have to keep it a while longer!