Reply to UK Based and Want to Build a New Controller

I have zero experience in modding any of this stuff. Just thought I'd get that out of the way straight off!

However, I've got a pretty nifty idea and would like to try and build something myself as it'll be unique and give me something to do!

I like the look of the MidiFighter, but from the UK it's pretty pricey to buy due to the delivery costs, which obviously can't be avoided. I had a scan around and reckon I can build something pretty nifty for the same-ish price.

My idea is to build a MidiFighter-esque device but with additionals panels on either side of the buttons. I would like one side to have parameter knobs, similar to the Akai LDP8 and the other side to try and do some kind of Kaoss pad mod/thing.

I was believeing this would allow full control of cues and effects via buttons, and then able to tweak parameters via the knobs or the Kaoss pad on the fly to give an almost endless and limitless abuse to the effects.

So, it would be similar to a MidiFighter (or almost identical in part), but longer with an additional panel each side, one for a Kaoss pad and one for filter/parameter knobs.

How difficult would something like that be to build? I read somewhere about being able to use a DS screen mod for the Kaoss pad (and I have a DS I'd happily pull apart) and I assume the other parts will all be pretty cheap.