Questions,

Are the uprights from a scorpio with disc brakes the same as from a sierra ( expect the 5 bolds)
Are the parts interchangable, i mean can i just use the upricht from the scorpio with the stub ( 4 bolts) from a sierra ??

I can buy complete rear uprights from a scorpio for litlle money, and tought if they are interchaneble that it is easyer than making adapters for the calipers

yes, the scorpio rear uprights are the same, as you say, you just need the 4 bolt outer flange, (the inners are the same as well)