I've realized long lever brakes for my XB8.
This is a solution that widely improves the braking feeling. So I'm not talkin' about "braking power" which is enough even with the standard short lever linkage, obviously if you have a good servo !
Here in Italy I used to race those brakes (even though I used a slightly different linkage, due to brake only whith 1 front disk....but that's another story...
) on rally races, which are on tarmac. You know, tarmac has got a lot of grip and no bumps, so the feeling difference whithin the standard linkage was DEEEP! 
So I adopted same philosophy on my buggy, and it worked! But buggies need 2 disks, so here's the easiest linkage possible to mantain 2 disks whith F/R repartition adj.
To be really complete, the mod i'm going to describe needs "real" ferodo brake pads; Which I've made glueing xray steel brake pads on a real 1:1 brake pad, and "DREMELLING" them out: these ferodos give you less ON-OFF action, incredible durability, zero fading.
So, the simpliest solution i was able to develop needs:
_ 90° servo horn
_ 2 long type brake cams
_ 3 pieces of steel wire: 2 for long levers and 1 for their linkage
The rear lever is connected on the linkage whith uniball. The front lever needs a long hole (you cannot add another uniball, otherwise it will "force" during movement
). The long hole is needed when you give throttle, cause the linkage will rotate on the uniball, and translate in the hole...(it seems complicated, but believe me: it's absolutely EASY AND FLUENT). Try to figure it out... 
The red collars allows front/rear braking repartition adjustment.
All that mechanism needs only to adjust the braking end point, improving the servo braking stroke.... i don't know if you understand my english...sorry
Believe me, it's an absolute easy and fail-proof construction!
If you were very sharp and smart modellists (and you are...
), you could be able to get the perfect dimensions to build all that linkage PRECISELY in the "bubble" every buggy body have right over the throttle/braking linkage zone!! It will perfectly fits! 
Try these brakes, and feel the difference!