I've recently obtained via eBay a set of Brembo Discs, Calipers and Pads and intend to do the upgrade myself.
All LR parts and I was told by the Seller all designed to fit the non S/C L322. He had bought these to fit to his Discovery 3 having been told they would fit, only to find they would not. I am told you have to have at least the 19inch roadwheels fitted for there to be sufficient disc clearance. The only additional parts required I understand are S/C Disc Shields (which may have to be modified) and I've also obtained the S/C wear indicator just in case the attachment is different.
Again, I am told no different brake booster etc required.
Alternatives are the big Brembo Kits (F & R) but you are getting into thousands of £ for these.
JE Engineering (http://www.jeengineering.co.uk) based near Coventry were offering a L332 Brembo front brake upgrade for about £1250 + VAT