Reply to New Custom Controller - Looping Advice

Hey everyone, I didn't want to post anything up until I had a complete concept sketch and had my website up and running, but I'd appreciate your input. I'm making a set of MIDI controllers for Club DJ use, one for either side of the mixer controlling 4 decks. I will be documenting the making of these controllers on my website so that others may use the information to build their own.

Currently I use an XONE 1D and as far as looping is concerned only have a pot to control the length and it pushes down to activate it on the currently selected deck. This is ok for the moment as there aren't that many buttons/knobs on the controller, but if I'm building my own I may as well get it perfect.

Take a look at the attached picture and let me know how you would utilize the empty space for Looping/Moving, note that there is a button for each deck already that will activate the loop. Also any information on how you currently use loops with your existing controllers would be very helpful, the more the better as I'll try and whittle it down to what I feel will work the best for me.

Thanks for all the inspiring examples on the site Ean and also to everyone else that contributes here.
Monsta