There are several options for the Aristo.
The easiest way is buying the Supra TT calipers, pads, rotors and stainless steel brakelines. Expect to pay about GBP800 to pay for a brand new set.
The disadvantage of the Supra upgrade is that it is very heavy and a rather old design (the Supra was available from 1992 ...).
A better upgrade is to go for an Prolex big brake upgrade, that consists of 4-pot calipers, 330mm 2-piece rotors, which is a much newer, lighter design. Expect to pay about GBP1000 - 1100 for this setup.
Other options are ... TRD/ UCF30, Brembo, MovIt big brake kits. These kits are about GBP1300 - 1800