there are no guarantees that it wont happen because it depends on the offset of your wheels. one set of wheels with one offset wont scrub at all and you wont have to roll the guards, but then another set of wheels with only a few mm difference in offset may cause scrubbing and the gaurds will need to be modified..
then there are tyre profiles and wall designs. with one set of tyres i didnt get any scrubbing, but then when i got my 2nd set of tyres since the superlows they did.. walls that roll over slightly have less chance of scrubbing where as walls that are straight up and down have a higher chance of scrubbing.
if you dont have a credit card you can either direct deposit money (i'll pm bank details to you) but you can also use paypal without a credit card as has been explained here -
http://www.antrx.com/smf/index.php/topic,14173.msg224184.html#msg224184further on the shop, currently we're using paypal as our payment system.. but you dont have a paypal account? thats perfectly fine! we can accept credit card payments using the paypal payment gateway even if you dont have an account. if you're in australia, you can also pay with your bank account, but you need to set this up with paypal.