So you want to go through the expense and hassle of trying to fit Focus brakes just because you have the pads already? I'd take a step back and look at that you're trying to achieve!

I'm not too sure about the ST170 fronts but the rear's barelly fit under my 15's and they'll be smaller than the fronts, I have 285mm front brakes and they just about fit under 14's so with an educated guess I'd say the 300mm fronts probably wouldn't fit under 14's, I can't think of anyone I know who's tried it either