customizing/converting an old midi keyboard

[borg]

hello midiboxers.

i'm really new at this, and could use some pointers.

to get into all this diy matter, i thought i'd start off the easy way.  i have this old evolution mk-125 midi keyboard (really simple:  2 octaves, transposable up and down, pb and mod wheel, some buttons for channel, preset,...) which i opened up.

what i basically want to do, is turn this keyboard in some sort of drum trigger device, trigger finger style.

http://www.midibox.org/forum/index.php?topic=5820.0 (i know, might be easier, and maybe cheaper to buy this unit, but hey...)

8 or 12 drum pads, a couple of simple on/off buttons, and, if possible some rotary encoders.

on the inside, you can see the keys operate two 'pad surfaces' each (for lack of better name), so i suppose it is the 'time based velocity sensing', like the faster you hit, the higher the velocity.  i'm a total newbie, so correct me if i'm wrong.

from my first investigation here, you could use piezo's for this?

is this possible at all?

anyway, every suggestion/links are welcome. 

thanks, andy