Hawk is definitely one of the big players, but they don't make any rear pads (HPS or HP+) for the 02-04 SE-R. You should check out Carbotech Engineering, I know one of the guys who works there, Matt Nicholson who pilots a pretty quick b13 SE-R in autox, so they have a lot of Nissan applications, which is always nice in this Honda dominated world. Their products have gotten good reviews by users from this board.
http://www.carbotecheng.com/appguide-pads-nissan.htm
The Carbotech Bobcat is probably equivalent to the HPS. To my knowledge they are the only company that has complete front/rear pads for the b15 SE-R. Read what Sunburst03 has to say.
http://www.b15sentra.net/forums/showthread.php?t=92052&highlight=bobcat
I currently run Hawk HP+ up front and stock in the rear on TPM rotors, which is not very well balanced. HP+ is probably the most aggressive street pad you can get, they are very noisy, create an unreal amount of dust, but have eye popping stopping power. If you brake hard taking a sweeping corner, the car gets pretty squirrelly, the rear end actually fishtails back and forth. Not surprisingly, I'm asking for Bobcats both front and rear for my birthday present in a couple of months. BTW, I turn 30

maybe my wife will take pity on me and get me the Eibach sway set too...