99 Silverado 5.3L, need com. chip advice

I just had a 40 series flowmaster catback duels installed today. I have also installed a K&N filter and I am ready for a performance chip. I know little about the chips. I do know that the chips adjust fuel/mixes, adjusts the shift points and probably alot of other neat stuff. Everything else is stock and I am not interested in top of the line equipment. I just want to free up this engine's potential. Any suggestions or web sites where chips are compared? Thanks.