Kia Rio?

2 inches isn't really optimal for a 1.4, but if that's stock size, I suggest you stick to that.

The best upgrade for a Kia Rio is a surplus Kia Carens 2.0 diesel engine.

Failing that, mags with better tires are a must. The Rio's stock tires are pure crud. Stiffer shocks would also be nice, but those would be hard to find, locally.

If your current exhaust manifold (header) carries your catalytic converter, that's all that's keeping you from losing exhaust velocity. You might find that with a scavenger-type exhaust and a performance header, your car will sound poppy, sputtery and will not drive well at all at low rpms.

The better set-up would be to have performance headers, leave the stock 2" midpipe, and replace the muffler with a freer flowing one. Then change the intake out for a K&N head. You're done. If you want extra kick after that, get a piggyback performance computer, like an S-AFC or a Unichip. For 20-30k pesos, that'll add another 10-15 hp to the car. Beyond that, you're looking at expensive mods for little gain. Either you go full turbo (about 150k) or full naturally-aspirated (with cams, camgears, high-comp pistons... about 200k).

But really, the first thing you should consider is whether your brakes and tires can cope with more power. Do the simple stuff, then upgrade your car's handling.