There is a big compromise for the small form factor that can fit in the Stanley case however. Due to the low height requirement, I had to use the DP20V2A supply which has a max input voltage of 23V. 24V sucks a bit though, since I have some 24V stuff. I already had one these though, so thought I could use it. The parts I am planning to use for this are:
DP20V2A CV/CC Programmable Control Step-down Power Supply
XL6009E1 DC-DC Adjustable Step-up Power Converter Module
DC 24V Brushless Cooling Fan 25mm 25x25x10mm - this may not be used. I need to test to see how well it will work with 22V.
Once I get this printed I will post it up (if it works that is).
Update - Jan 14, 2019
I did get this printed but had some issues with it, which I think are now fixed in the 2nd version (printing that now). Everything seems to fit in the old version pictured, but the handles are flimsy and I wanted to be able to use a dual banana jack which has 3/4" spacing (19.05mm). So that required some re-working (a lot really). The latest version is pictured last and will be uploaded when/if it works out. I am still waiting on parts from China so I may just post it up as a work in progress since I am 99% sure the parts will fit (waiting on the 4mm banana jacks).
My DP20V2A supply fried itself last night though it never received more than the max 23V input (never more than 22V actaully). Looking at the board I suspect that the inductor may have been pressed against a component on the board due to a manufacturing error, but since it was an Ebay purchase I am doubtful there will be anything the seller will do. Went ahead and ordered another one which will take a couple weeks to arrive. I did make some more changes to optimize the design a bit more (pic below). Once I get it printed and tested, I will upload it and post a link.