The rear on the S13 will probably fit the set just fine with nary an issue. You can buy it and be just fine with that
Stock fenders with the 275 will fit with barely a roll with this wheel width and offset.
Take a look at the thread below and note: The RA1s DO run wide, so with the NTo5s, you will be able to get away with it!
http://www.freshalloy.com/showthread...a-9-inch-wheel