i agree wit crxb16er. v-tec cars generally have high compression. you might be safe boosting 6-7 lbs. but before you boost any more, you need to lower your compression and upgrade.
your fuel system and pistons are maybe the most important things to research on and upgrade.
you might also want to look at how the last owner came up on those 100,000 miles. aggressive driving, could mean upgrades are more nessesary before you go turbo.