there used to be a chap selling sets on ebay but delivery times were a bit hit and miss according to feedback, m99 sell them but all their parts are copies of other peoples stuff thats made abroad and drop shipped in the uk so service isnt great and fit can be variable.
its also worth having a look on www.fiesta-mk1.co.uk and on www.xrtwo.com
both sites have a wealth of knowledge on where to get the hard to find parts for the early fiestas at the best prices, some real inspirational cars on there too