In terms of power supply, I agree with @Bassmidget209, you’ll probably want it underneath the board. I saw that T-Rex have a special bracket for that: https://www.t-rex-effects.com/brackets
On my board, I couldn’t find a bracket and didn’t want to drill, so I actually used some of the heavy duty removable “picture hanging strips” - it’s Velcro really, but can easily be removed without leaving glue marks or ripping the paint etc: https://www.3m.co.uk/3M/en_GB/p/d/v000273808/