in rims...maximum we have seen is 17inch rims in baleno...but then yr suspension life is gone by half...so u have to go for 1 thing..it will be good that u get 15inch rims with 205/50/15 tyre size
go for plugs and hot wires...plus airintake will create tunning issues on CNG otherwise good to go....
if going for performance...get new headers and downpiping...but do keep in mind...to much noise and less fuel economy
if u want to have some decent looks...then get yr front and rear bumper extanded...and new side door panels and new spoiler.....get HIDs and angle lights.....i saw once in a baleno 99 modal
what else u need?