I wanted a compact power converter. I found the ZK-4KX on Amazon for a great price, and I liked it so much I decided to make a case for it. It utilizes (extremely handy) XT-60 connector and a DC power jack for input (or daisy chaining multiple together). I can run off of any 5-30 DC voltage source. I run mine off of an old 19.5V laptop power supply. It also has Banana Plugs and XT-60 Connectors for output.
The connectors fit pretty well, but you will likely need super glue to hold the output XT-60 connector in place. The lid fits on fairly snug, but if you want a more permanent solution, again, use super glue. You should still be able to remove the buck boost converter if you ever need to get it apart. Below are links to the components I used. I hope you find it useful.

DC-DC Buck Boost converter: https://www.amazon.com/dp/B0978T3JKH?ref=ppx_yo2ov_dt_b_fed_asin_title

Banana Plug Jack Socket:
https://www.amazon.com/dp/B07CQSCK9J?ref=ppx_yo2ov_dt_b_fed_asin_title

XT60H Connectors:
https://www.amazon.com/dp/B07VRZR5TL?ref=ppx_yo2ov_dt_b_fed_asin_title

Round Button SPST On/Off Rocker Switch:
https://www.amazon.com/gp/product/B00AKVBEN6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

5.5mmx2.1mm 2 Pins DC Power Jack Female:
https://www.amazon.com/gp/product/B01N8VV78D/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1