like clarkson says you dont need a servo, the CE beams come with two lots of stud mountings and will fit any bus from 54 to 80 balljoint beam check it out here... http://www.creative-engineering.com/cgi-bin/shop/web_store.cgi?page=beams.html&cart_id=4764534_10761
both Easy and Ant on here have them fitted and i believe they are quality.
If you do go the disc route and you want to stay wide five which most people do, the kits can become very expensive (upwards of £700). If you buy a weedeater, its narrowed already and can accomodate the latebay brake setup (complete cost me £200 for both sides from FBI spindles/discs/backingplate/calipers). You would be able to fit narrow five to wide five adapters and keep the wide five tyres with no increase in track.
Weedeater beam £450
latebay front disc brakes (complete) £200ish
112 to 205 adapters (pair) £100
you would still have change of £1000 :wink: