I've always believed cams and ecu to be a finishing touch.

The wrong cam choice can destroy an engines potential power. Wait to do cams after you've modified the engine as far as exhaust, intake, and whatever other little things you want done. Then get dyno'd find out where the power of the engine lays and make a selection based on that info, then fine tune the computer to the cams and you'll be set.

I'm more of a muscle car man where the cams can make or break the whole engine's powerband and I'm not too familiar with honda's and VTEC but all engines generally mod the same way with the same general results.