The Lippert Kwikee 38 Series Electric Step - 1 Step - 4" Drop/Rise - 24" Wide - 300 lbs # LC3723383 are the replacement for the original 38 Kwikee steps you mentioned. You will just want to confirm the step dimensions of 24 by 10-3/4 inches and the mounting dimensions of 25-3/4 wide by 5-3/4 tall by 11-3/8 inches deep. view full answer...
The tubing on the aluminum uprights for the Stromberg Carlson RV Exterior Ladder # LA-401 that you referenced features an outer diameter of exactly 1 inch. I have attached a short video demonstration that you can also check out. view full answer...
I believe I have found the helpful article section you are referring to and have attached a link towards the bottom of this answer page.
For your 2015 Jeep Wrangler Unlimited the Etrailer Preferred parts are the following:
Roadmaster Base Plate Kit - # RM-521448-5
Roadmaster Nighthawk All Terrain - # RM-676
Hopkins Custom Tail Light Wiring - # HM56200 (cut off 4-Way connector and wire to tow bar connector)
Air Force One - # SM99243
Tow Bar Cover - # RM-055-3
Brake-Lite Relay Kit - # RM-88400
Tow... view full answer...