Most standard pads have friction coefficients of 0.4 or so but are designed to be effective from low temperatures for normal driving. Several pad manufacturers including Mintex, Ferodo, Pagid etc. etc produce pads with higher friction coefficients, and most Pagids tend to provide approx. 0.5 and good temperature fade. There are also specialist pads (typically metallic compunds and/or kevlar) that produce massive (0.65 and above) friction coefficients, but they are useless below 200/250 degrees and will rapidly degrade your discs (not mentioning countless pedestrians casualties who will not wait for your pads to heat up nicely...). My advice, would be to go for 0.50-0.55 friction pads designed to operate from low temperatures (150+ deg) up to 550 deg for fast road use. If you intend to use the car on circuit, just temporarily swap out the pads to race pads.
The pagids are probably better than Mintex 1144s (0.44 ). I would chose Pagid RS4.2 or RS 4.4 (so called blue or red). Another good pad is Ferodo DS2500. In any case, be careful how you run in your new pads (avoid immediate prolonged hard braking when theyre new or youll glaze the surface of the pads and make them useless)
I hope this helps. have fun
Philip