The keyboard is probably a little matrix, if the controller isn't built in you could connect it to a Teensy (or similar) just like you would a standard switch matrix. Then connect the Teensy to a USB to bluetooth board (adafruit has one) and it will work. If the controller's built in see the below - same story.
The "mouse" would be the trackball/optical thing? It's probably very small and proprietary so you'll have to work out what the pins do (unless you can find something online where someone's already done it) Part of this will mean putting voltage into it and if you put it in the wrong place there's a chance you'll damage it, so be prepared to buy a couple. Reverse engineering hardware (working out how something works without documentation) isn't really a beginners topic but I wish you luck if jump in the deep end.
As an alternative to using the actual mouse you can configure keyboard keys to move the cursor, it's less accurate but I guess this is only for occasional use so it could work. Not sure if the Blackberry keypad will allow you to press any random keys together (search: switch matrix diodes) but some shouldn't conflict.
Once you have anything working you'll need to cram it all in the case which will be a challenge in itself.
This is deliberately vague as you didn't want the spoon - this is the right place if you have any questions