i think the best engine to put in would be a 1.7 puma engine,

it will require mods to fit but once in over 120 brake with more to be had

obviously a racing opuma engine is better but they cost alot more and it is possible to get the same power from a standard one.

plus a high bhp wont be needed as much in a ka as you want to strip it and they dont weight much to start.

as for brakes itd get mondeo mk3 calipers and st170 discs for a cheap but good setup, and itll fit under those wheels i beleive

get some more pics up