RopieeeXL is typically the easiest. Pretty much flash and go. Though the only thing i’d say: Make sure you connect the network BEFORE turning on the pi. Otherwise it gets a bit fussy on first boot.
Dietpi is also good but a bit more involved. I’d say go ropieeeXL unless you have a reason not to.
For power, the ideal solution is actually to use a single 5v PSU to power both. You can bypass the onboard 24v->5v switcher by connecting to the pins directly as shown in the pic below.
Just need a DC terminal and male to female jumper wires. Both of which are on amazon for a few dollars.
Though whilst this is the best in terms of sound/power cleanliness, you can also either:
- Leave the power jumper on the board, connect a 24v PSU to the pi2aes, and it will power both the pi2aes and the pi.
- Remove the power jumper from the board, connect a 24v PSU to the pi2aes, and a 5v psu to the pi itself