Well I have finally finished my brake upgrade on my ae86. I investigated many options and ended up going RA40 struts and brakes. This combination bolts sraight into sprinter, does not need a change of steering arm and does not mess with your scrub radius. The calipers also fit up to your old brake lines. It ended up costing me about $800 in the end. Here is what I did for all the other ae86 owners out there.
Things I purchased:
Ra40 ser I complete struts (SerI because your ae86 strut insert can be used in this one. They are the same length)
DBA slotted rotors (Not cross drilled because for daily driving the temp. variation is too much and will end up cracking your rotors.)
Bendix 4wd compound pads (High kevlar/metal content)
2 x Caliper rebuild kit
2 x Wheel bearing kit
2 x adjustable spring seats/ spring tops and 220/260 progressive springs
Once everything has been purchased, strip down the serI ra40 struts and clean then. Replace the strut inserts if they are buggered or if you have good quality ones in your ae86 put them in. Replace your wheel bearings, fit your new discs, rebuild your calipers.
I was going to use ra40 springs but found it was rather easy to convert to coil over. (I chose not to use the ra40 springs as it was going to require a lot of arsing around to find the right height.) For $319 I got two adjustable spring seats, 2 x springs and 2x spring tops from Fulcrum. The old spring seat was ground off but the weld was left there. The adjustable spring seats were then pressed on down to the weld. Fit your springs, spring tops and ae86 strut tops..... you now have coilovers.
This combination now bolts into your sprinter but you must run 14inch wheels...no more 13's now.
Result: The car pulls up faster and brake fade is no longer a problem. It also looks cool behind big open wheels.
Any questions mail me here , or if you are in Brisbane and can get a hold of me you can have a look at it sometime.