As Icedout said, bar is the metric measurement for pressure. The way Vandy can be reading in bar is by having Greddy peak/hold gauges (or other non-American gauges). These gauges measures in bar and have a feature that remembers the highest reading the gauge has seen since being reset.

As for answering Vandy's original question, don't go on to an exhaust until you have A) bought a boost contorller of some kind and B) ported the crap out of the turbo if you're going with a 3" exhaust. Even a 14b has to be ported alot to avoid boost creep on a larger exhaust. But as I said, get a boost controller. That and a boost gauge should be the first two mods one gets in my opinion.

Hope that helps.

Matt