To OP
read the how to mod lists running around. should cover most of the basic mods
if it is for her, then i say do nothing you should have the faster car!
if you take the GT then here is what i would do. figure out a budget and a goal. if you just want a lil more power stay NA and do the following. if you want more then topswap it.
1st:
Build a FWI
Next:
have a local shop remove the Ubend in the exhaust
Next:
a HV3
if that isnt enough you can do a front PowerLog. but if you get the HP bug then you might as well do headers and get ready to do a swap anyway