your only talking about 3-6hp and 2-5ft/lbs torque. So it not really that big of a deal. Youll get more hp out of an exhaust or with an intake manifold. if i were you i would save up and and invest in a turbo kit, youll gaine more hp than you would with 2k in aftermarket bolt-ons.
Check this site out, it will be worth the visit
http://www.hahnracecraft.com/auto/eclipse/eclipse.htm