Cheapest way may be to use a turbocharged mx5 as your donor if you can find a rusty one. Just don't drive the donor first or you may never build the zero.
To summarise from acquired knowledge on this forum the list of joints on the Ford sierra based zero front hubs are as follows.
Top Wishbone to dummy strut/wheel arch carrier = Transit drag link
Bottom ball joint - Lower wishbone to sierra hub = Astra Mark 3 lower ball joint (thanks whiz)
Extended escort steering rack to sierra hub steering arm = Sierra track rod end
Hope this helps
Ozz