i wouldn't say "more pots" = better. I have seen 10 pots Wilwood but i strongly believe my reasonably priced good old AP Racing 4 pot is more capable to suit my need.
magnesium caliper? will that be cheap?
also, those 4 pot are mainly for track use and is strictly bounded by regulation. you don't see any group "A" running 6 pot, do you?
a good 4 pot with proper brake pad can out perform 6 pot easily on street usage.