Hi there buddy, in theory, you can run this tyre on the front or the rear, but I reckon if you was to put this tyre on the front, try to go for a 2.25 just for the extra grip. If you was to put this tyre on the rear, go for the 2.10 if you haven't got massive heeps of tyre clearance between the wheel and the frame. What I've found from personal riding, when I have a buckled wheel or a broken spoke, you find the tyre will rub on the side of the frame if the tyres too wide... which isn't good. If your wheels are perfectly true, then you should be fine.
Hopes this helps
Robski