Supercharger. The K&N will rob some power because it is junk. If you want long tube headers you will lose lower end power but gain top end power.
Stock - 181rwhp/230rwtq (80*/40% humidity)
Stock TRD S/C - 229rwhp/280rwtq (93*/44% humidity)
TRD S/C, K&N CAI, X-1, DTLT, URD CBE = 297rwhp & 320rwtq - 70wrhp/40rwtq gain
I later went on to dyno 356rwhp/366rwhp after building a motor with lower compression, upping the boost a little, and adding a true dual exhaust (with the same K&N cai).
The long tubes comment is accurate on many other vehicles, but not for the 1gr motor. The long tubes have gains only in the mid range spanning about 2k rpms. You will only see high rpm gain under boost if you have a catback that allows for extra volume. Also the low end loss is not as bad as people claim it is. This dyno is a bit misleading as they didn't start the pull until about 1800rpm vs the 1500 of the stocker.
I want a supercharger bad. But dont.have 5g for it. So its headers back exhaust and some kind of programer.
HP costs $$, simple as that. For the more budget minded, cai, headers, catback, and a tune should net you a combined 30-45hp, on a good tune. The URD MAF Cal is a good option for a simple solution. For a good tune that will net you the most power, you will need something more powerful like the MAP 2 ECU or MAP 3 ECU.