17's probably don't require the rain gutters to be trimmed, but I'd still be checking the clearances. Get the stick-on style weights when the wheels are balanced. The clip-on style have a tendency to get knocked off by the LCA's.
A 1" additional drop via a longer shackle may or may not require a pinion wedge to correct that angle. The nose of the pinion will angle down more with that. This seems to vary between truck to truck so that should be checked. If it is out, the resulting vibration will tell you for sure. The pinion angle on a 6" drop is built into the kit, but if you go lower, then that angle has been modified from the original design. Maybe/probably only need a 1-1.5 degree wedge. With a wedge that shallow, longer U-bolts would not be required. The wide end of the wedge would be towards the front of the vehicle.