If you have to pick from only those two, I would say go with the SR-05. You don't really want a low downforce body for super stock on black carpet. With the corner entry speeds you're going to have an SR-07L is a bad idea. Heck, even for 17.5 on black carpet the SR-07L can be a nightmare if traction isn't up. If you're open to other options the SR-06 series is more suited to 13.5 cars. Mon-Tech M20 is a great option as well.