You might want to try just not going 140mph. That'd be much cheaper than forking out on new brakes.
But anyway, I had the standard Renault pads with Max Groove discs on the front when I got my 182 (don't change the rears, there's no point) and to be honest I thought they were absolute pap. I upgraded to DS2500 pads and the improvement was incredible. A few weeks ago I had the front and rear discs and pads replaced with new Renault rear discs and pads, and Brembo Max Groove discs with Mintex 1144 pads. Whilst I was having that done I got braided hoses and dot 5.1 fluid put in. The car now stops incredibly well, and without going to race pads such as 1155s, Carbone Lorraines or Performance Frictions (I was going to but opted against them due to the aggression of the pads and the monumental dust levels) or 4-pots, I now have apparently the best road set up I could ask for.