to freshen up the whole motor like magana said would likely run you at least $1k in parts, then if you cant do it all your self, add more for labor. cams and valvetrain alone could cost up to a grand just by themselves depending on what you get. plus you need to think about tuning it, you will need something for that.
a good complete used JRSC kit should cost you around $1000-1400. dont just buy the first one you see for sale, make sure it is complete and legit, or you will have a good time trying to piece it together. i bought one for 900 but it was missing 2 parts, luckily they werent extremely hard to find. jrsc is really fun, your little hatch should be able to see 12s in the quarter pretty easily im thinking. but keep in mind that the power potential is limited with the supercharger to about 250ish, unless you spend more money on a LHT cooler ($1k). i still miss my jrsc setup sometimes, it was nicer and more fun to drive on the street than my turbo setup now.
the third option is turbo... easily make more power than the jrsc on your stock b18c, but to do it right it will probably end up costing you at least 2k in parts.
any of these will require tuning, dont forget about that! do you have a local shop that you deal with already?