Hi James.
I am running Hawk ceramic pads on the front, Porterfield road pads on the rear.
Hawks are a lot less dusty than the OEM pads I had on the car before.
You can have them done for a lot less over at Whifbitz in Enfield. Paul Whiffin can handle the purchase through the shop website, Darren will be the mechanic that will do the installation for you.
He is a darn sight more reasonable than Lexus in terms of his hourly rate, and the work will be done to a better standard (Darren treats everyone's cars like their his own).
Here is the link to the shop: http://www.garagewhifbitz.co.uk/lexus/is-f.html
I'd be tempted to go for a full set of the Porterfields. These are very good pads. I had them on my Supra for a while. Really pleased with the bite, longevity, low brake dust etc.
I'm sure Paul could offer you a deal for the discs, pads, fitting?
Just drop him an email. :)
Hope this helps.