Well I too was concerned about the power, however I did not want to drill into the cabs in any way, the lead therefore from the top cab comes out the bottom corner and rests on the lower edge of the cab little black tape to keep in place, the bottom cab it comes out at the top, this way you can power them and just tuck the lead in the gap between the two cabs with the TC rough covering it just stays there.
It is easier and more out of the way than say a power supply for your pedals, you just need to plan the routing.
If you are willing to drill our cab then you could drill a hole to thread the cables through to the back of the cab and then fit a female DC surface mount to the back and plug in that way but I did not want to change or damage my cabs.
The way I have done mine you could remove and never know they had been there.