Best accessories for MPC Key 37 for on the go

I just bought an MPC Key 37 and looking for ideas that make using it better.

Anybody using any shelves that attached to the rear of the unit using those screws in the back?

I was thinking it would be cool to hold a speaker or a battery somehow connected to the MPC in some way. a shelf of some kind?

Handles?

Regard a battery, you may want to read this.
viewtopic.php?f=48&t=218062

As for the screws, do you mean the 7 small screws that attach the black base to the read case on the underside at the back. It so, I wouldn't want to hang anything off the back here. the leverage pulling on the screws is likely to cause damage over time, any accidental knock will cause a greater impact. I would look more at adhesive velcro, the 50mm strips they use on guitar pedal boards.