Personally I would go someplace other than LCI for information. Try etrailer.com. LCI has not been friendly with end users and prefers to deal with their dealerships. LCI also makes steps under their name and if I remember correctly they are more expensive than the Kwikee models.
I don't know how many steps you have but from the width I would guess you are going to be using a series 32 step.
My rig has a complete steel cage around the area where the steps are mounted and so I can't answer your question about the suitability of mounting to your battery box, but I doubt if is a good idea.
Did your rig come with a option for electric steps. If so take a look at a new one at the dealers. You could even contact Camping World in Wilsonville I believe, they will know exactly what you need. I just noticed you're in Bend, Eugene is closest to you.
