The truck looks cool!
You will be a lucky guy purchasing it! I too wish that for you!
I'd like to own one also some day. But so far it's only drool!
The sleeper you have was made by Able Body. At least judging by the pics. As you can see it has two cut outs for the exhaust mufflers. The LH one was gone in unknown direction. Or possibly the sleeper has come from another truck which had two stacks and yours had one.
Speaking the matter you asked I doubt you'll be able to find stainless skirds for that sleeper. They seem existing in the past but during my observations on different on-line truck accesory shops in the last 15 years I haven't seen any offers on those. Also a point is a R-model cab is not designed well to acomoddate straight skirds. It has rounded rocker panels which wouldn't suit flat boards. Or at least they would look wierd there. For my needs I fabricated stainless skirds for a sleeper but declined idea putting them on the cab. Sure that was a matter of my taste. Fabrication of stainless parts turned out into more complicated deal as it looked to me originally. The material is harder than common steel so you need high quality drill bits and notable amount of labour to attach marker lamps.
The truck on the picture (not mine unfortunately) has a sleeper similar to yours. It's Able Body, I checked it out in person, there's a tag riveted to the back wall. As you can see there are stainless skirds attached to the bunk only and they look nice. I don't know where the owner accuired them from. Of what I know definitely they were put in place a long while back. Too possibly they're hand made.