Since you own Pro already, you should use its own Physics Engine which is btw. based on ODE. Start with something simple...

You would need to spend more time if you have to integrate a different PE into GameStudio.

I have used the GameStudio Physic in a few projects. Sometimes it is neccessary to fake the physics if you find too different behavior on very slow and very fast machines. Depends on your type of game, too.

-- slacer