The only "bolt-on" worth doing for that car is a turbo kit. I/H/E will add minimal power on that tiny 1.6L - not worth the money IMO.
If you don't have enough money for a turbo kit quite yet, I would opt for a nice spring/shock combo and maybe some lightweight wheels with sticky tires.
My 92 Sedan barely had over 100HP, but i had Koni Yellows w/ H&R sports on sticky tires and it was still a lot of fun to drive. :thumbup: