help with what rims to pick

i have a 01 sport trac truck and what to know if i want to bring the wheels out just past the fender what offset to go with my stock 16" rims have a 12 offset they say and the rims i can get is a 16" with a -6 or a 17 with a -12 and will be running a 265-75 tire thanks

 

[stang7tl]

here is the link of the rims
http://wheelsandspinners.com/product.php?productid=46&cat=0&page=2