Nobody really chips the OBD2 ECUs. Chips are useless though, get a Hondata s100 for $245 and have it tuned on the dyno. That's on top of the cost of getting an OBD1 computer and assorted wiring, but you'll have to do that no matter what if you have an OBD2 car. Otherwise you can get the AEM EMS which is available in plug-n-play with the OBD2 wiring.

The ability to get easy horsepower out of an ECU chip is a total myth. You'll get a little better throttle response and maybe a couple more horses but nothing major. You make power by getting a good air-fuel mixture for your particular setup which is undoubtedly different that whatever car the company selling the chip used to make their program. These "Mugen" programs (which most likely were pirated) for example, were originally designed for their Formula 4 motor. It has insane cams, a 9500 RPM rev limiter, 13:1 CR, individual throttle bodies, etc etc etc. Not to mention that with the program, many sensors are disabled (they're not there on the race cars) and for the most part you can't even get the thing to throw a code when something's wrong. Regardless of the fuel tuning, you wouldn't want to run that program on a street-driven car.