Reply to DIY Controller extension and stand for a Mixtrack Pro

Hi,

I have a Mixtrack Pro and I want to build a case so it stands at an angle and then Add something at the bottom and top for extra buttons pots and so on.
This is what ive come up with so far:
Zusammenbau.jpg
HintenBlech.jpg
Frontblech.jpg

Now before I can start building i need to decide on buttons, pots and faders:
Buttons:
- For the 2 blocks of 4x4 buttons I wanna use arcade buttons or if possible arcade buttons with light like the Midifighter 3D or maybe even something touchsensitive like the Kontrol F1.
- The rest of the buttons can be different. No idea what would be best i want to use them for things like a shift button, effect/s on/off ect.
Pots:
I need 4 in the front and 8 on top. I want to use the front ones as filter and gain for each deck, and the top ones for effects.
Faders:
I need just 2 to be used as volume faders (the ones on the Mixtrack Pro are 55mm long and I'd like them to be around the same lenght)

The problem is I can build the case and all that, I should even be able to solder everything together too but I have no Idea about what kind of pots buttons and faders to look for all those Ohm numbers mean nothing to me^^ Im a Mechnanical not Electrical Engineer. So I need some advice on what and where to get these parts. (If possible in Germany)

Then I need to decide on a midi brain what would be best? I'd like to connect everything via usb and it would be nice if I didnt have to program a driver myself^^

Ok well I hope you guys can help me out.