Pete 378 / 379 Above Frame Exhaust retrofit?

Planning in the next year or two of kitting together a truck out of parts and due to some 'specing' issues I was wondering about the Peterbilts that run the high mount / above frame exhaust.

To keep the rig short for maneuverability, wanting to run a drop axle, and still be able to have a fuel tank hung under the passenger door that is larger than 90 gallons, I can't see any way around having to run a above the frame exhaust, like is pretty standard on KW's.

The truck is going to be a 379, or 378 Peterbilt, I've seen a couple that have the high mount exhaust, but they're all single stack's. Aesthetically I'd prefer a dual stack setup.

Also beings I'll be kitting this truck from parts, is there a difference in cabs? I'd imagine there may be some heat shielding that I could add on, but as rare as it seems this setup is from the factory, It would be pretty hard to find a used cab like this, and the 'low mount' setups are dime a dozen.

To give a reference the truck will be a shorter wheelbase tandem drive axle, with a steerable drop axle, wanting to keep the battery box under the drivers door, and have a fairly long single split fuel/hydraulic tank under the passenger door continuing behind the cab as space allows with the drop axle.

Truck is going to be used to pull a lowboy, but I'll more than likely end up with a belly dump pretty soon after it gets built. So basically a construction truck, in addition to facilitating the long single fuel tank it would probably be a good idea to keep as much up and out of harm's way knowing I'll eventually be jumping up on windrows to dump a future belly.

I know this one is kinda far out there, thanks to anyone with some insight!

 

I can belive that about ridiculously priced simple exhaust components. An exhaust elbow to fit 'around' my 90 gallon 23" diameter fuel tank I think ran $450 3 years ago when I re-built my 96 Pete, and it's not even chromed! That wraparound style works for my current setup on a dump truck, but for a transport truck knowing fuel consumption is going to go up significantly, and I'd like to have a toolbox/step mounted where a 2nd fuel tank would be it just won't work on my future transport truck.

Here's a schematic from one of the online parts vendors of the above frame rail setup I'm after Flightline: