exhaust is one of the most useless mods unless you have Forced induction...spend $600+ for less than 3hp
get an intake, headers, crank pulley, maybe spark plugs, dont know if there's a piggy back to control Air/Fuel ratios and VVT for toyota like honda/acura has for the AFR, Vtec and timing (V-afc = i have one

)...and after these mods, think of getting the exhaust....or save the money and get turbo kits starting from like $1200 and just go from there upgrading the turbo kit/engine/internals...IF you ever decide to spend this much money.
BUT in any case your car is very slow so save yourself the money towards your next car

...j/k happy moddin'