OK, I'm gonna assume that means forward facing horiz. dropouts. So do you have a rear wheel yet? If so you'll have to figure out how much tire clearance you have to the chainstay bridge from the rim as the wheel drops out of the dropouts. If you don't change wheels often then just get the fattest tires that will fit between the chainstays even if you have to deflate tire to get the wheel out.

Choose your own adventure.