I've had a couple of them, one of the earliest runs, and two more I got for junkers to build my PRR D16SB out of salvaged parts. So I've seen a lot of parts.
Those tender trucks with the wierd wheels are just the worst. And there really isn't any room. The only thing I'd consider is trying to stow it under the tender frame above the axles like a DZ126T.
If you want a really good 4-4-0 that's more 'normal', take a deep breath and get one of the Atlas ones, the performance and design of those is just stunning.
https://www.spookshow.net/loco/atlas440.htmlLike the 2-6-0, those were a Micro-Ace contracted locomotive. I added weight to my tender to improve pickup, hardwired the tender to the locomotive to help that, but if you can actually find one....they have become kind of rare.
he only thing I'd consider is trying to stow it under the tender frame above the axles like a DZ126T, or an 'above the deck' coal pile. I added a styrene 'frame' under the tender because of that big honkin' gap under there, but there is room between the axles and the floor.
The 'coal bunker' added here is all cast metal.

Link:
http://www.randgust.com/S&T409.jpgThe whole design is tough because you just need weight everywhere once you stuff the pickup and the motor in the tender, and are pulling from the front.
Oh, and as I remind people constantly about my Climax A's, in the kerosene headlight era 1800's, you didn't keep them lit in the daytime, so a bright LED in there is completely inaccurate. Once you had a steam dynamo and electric headlight, it was more SOP to run the headlight in daytime.