Can't add much to what Uncle Bob said. The "look" will be fine with the mismatch 15's & 14's, and a lot will depend on the stance with a full fendered car. Tuck the fronts up into the fenders and should have a sweet rake to it. Post up some pictures when you can. Here's a link to a post from Don that explains the necessary resizing unless you have your camera set for tv/monitor size files.
http://www.clubhotrod.com/forums/showthread.php?t=47288