You don't have to lower it. It just looks better. I think if you go with the shortest fender like I did, lowering is a must cause it will look goofy otherwise.

 

It's nothing like a hard tail

Many many K's travelled and no issues...

 

As one of the other folks suggested, get a danny gray from sterling seats on ebay. MAKE SURE YOU GET GEL. I put this seat and progressive shocks in rear. Closed up gap between seat and fender completely and the ride is awesome. Lowered the back 1.5 inches. I did a 3000 mile trip this summer with no butt pain...awesome. We did 300 miles per day. Hey, also, if you lower the rear on the rocker, the std. rocker bump stop is too thick, easy fix is to buy a rear bump stop fpr an 07 softail. Its only 5 bucks. Unbolt the rocker one and pull the 2 rubber plugs though the same holes with some pliers and it fits right on.