I think your confused on the tall skinny issue. the first link takes you to the "Other" tire available on the 4x2 3/4 ton burbs. its the load range E and will in most cases fit your rig.
without a lift kit I would find it hard to put bigger tires then a 265/75-16 but the second link if for 285/75-16. they are still tall but not so high as to prevent fitting under your truck. the 285's may rub when turning if the truck sits low.
one of the bad things about really tall is very poor handling if the side wall isn't strong enough. you can roll a tire off the rim on a truck that steers poorly
here's a link that may help.
use this to figure out what the right size would be? if the rpms at cruising speeds are more then your rig can take then add tire height.