Defender 90 brake upgrade

Want to upgrade the non vented disks / rear drums on my 1991 200tdi 90 to something a little better. My previous TD5 110 had amazing brakes, so am looking for similar. What options are there that dont cost the earth? Disco axles seem to be available at sensible money, are they a direct fit, and are the diffs the correct ratio, or will they need swapping? and can they be swapped. What about servo / master cylender set up, would they need to be swapped as well. I have to stress my current brakes are in good order, they are just no way as good as my previous TD5 110.

fit disco rear disc axle ,the 110 and later 90 vented calipers £60 ish,vented discs £20 + pads £20 dont need to change any thing else except a couple of brake pipes

So the fronts are fully interchangeable, excellent, and the disco has the same ratio diff?

Disco one the same.