Intake, anything is fine to be honest.
Exhaust, go Racing Beat its quiet, but loud when you want it to be loud, or go Mazdaspeed Axleback (mazdastuff . com) and its a deep throaty sound.
i like my injen cai, K&N is also a good choice. lol, hell all of the name brand intakes are good since they're all pretty much the same thing. if you're on a tight budget the simota cai on protegegarage.com is a nice choice.
and for exhausts, it's mostly sound preference and how much you're willing to spend. you can get a good idea of what a few different exhausts sound like on this thread here:
a lot of people have just gotten an ebay CAI and thrown a good K&N filter on it. might sound cheap but it makes a lot of sense. all it really is is some piping with a filter. the piping doesn't need to be anything special, but the filter needs to be good. that being said i have a K&N typhoon CAI, no complaints from it.