I know its basically a partial "Tremor delete" lol, but it seems like that is all that is available right now because people just love the tremors, I just wonder if it'll look just as good but ride even better with the standard setup.
I believe the 20inch wheels will give you better on road experience. The 18 inch gives you more sidewall for off roading. Its the same deal as the Jeepers. They run 17" off road and lots of cool "mall crawler jeeps have the 20" dished out wheels that would get trashed if they ever left the pavement.
Depends how you plan to use your truck. There is no wrong answer.