Yes, i think google sketchup would be an awesome program to make models for the engine, it's quick, easy and the models can be very precise. I've been working with the program myself and have been modeling vehicles and weapons, but haven't been able to put them in any games becuase there's barely games that support it at all.
So if you put in support for sketchup, i'd be really happy. Awesome and easy Modeling program, with an awesome and huge engine.