They do offer longer bolts for bikes with the backrest. I installed the brackets on my Raider (no backrest). Get the 106 not the 105 brackets. The holes on the fender rail are too far apart to use the 105's. Check with the company you order from, the kit should have extra spacers included. My kit only had the 4 slotted mounting "bungs" with no extra spacers . I had to get some extra spacers fabricated to make the brackets work.
About 4 days for my original order. It turned into a headache and I ended having a friend make me some spacer at her work. I did mine a little different. I used 1/4inch spacers on the rear fender rail bolts. Then I used 1/4inch spacers between the rear of the backing plate and the locking mechanism.
This made the rear bolt not stick out quite as far when the bags are removed. My whole project ended up taking almost a month trying to get the right parts. Yours should go much quicker.