A full-on B16 swap used to cost between 80-100k pesos, depending on how much needed to be changed. I think the ESi's fuel pump is strong enough for the B16, but you'll still need a whole shebang of wiring to be done, and that's what costs.

If you're not into drag racing, and you're not going to change anything else on the car (shocks, springs, tires or brakes) to cope with the extra power, then a D15B swap is enough. I don't know the cost, or if you could possibly just swap in the head and ECU onto an LXi's 1.5, but I'm wagering it's 50k or less for the entire project.

A 130-hp D15B-equipped ESi or LXi is just about quick enough for daily use, and would be fun on weekends. With proper intake and exhaust mods, it would be a near match for a stock SiR (lighter body).

Up to you what you want, but if you do go for more power, make sure you spend for good tires... and in the case of a B16-swap, good brakes and a better suspension.