Outer Limits 4x4 Board

Hi all, was just wondering wot was involved in changing the Seira's drum brake front end to a disk brake front as it will be my sons car. Is it easiest to just buy a complete housing end to end and if so wot should I expect to pay for one.
Ta Jafo74

Gday from New Zealand. I've done this conversion to my 1982 Sj410 (1L sierra) by swapping over the rotors, calipers and back plates from an 85 sj413 which i think is what you would call a Narrow Track (NT) sierra the 1300 engined version. the only thing that didn't just 'Bolt up' was the small tab that secures the break line to the chassis. But that is easily opened up a little. everything bolts up very easily. Other than that it all seems to work fine I've ran it for a few years now with no troubles. it's not as good as having sj413 breaks because a 413 has a break booster but they are better than drums and are much easier to look after and handle sand and mud much better that the old drums. Cheers, Hamish.