lighting - compact fluoros
fan - CPU fan you knw the ones in your comp might be a bit of work wiring it up to the mains..sorry dont knw how
ducting - im sure you can find somthing that will go on the cpu fan...
filter - you can either buy a carbon filter they can be expensive do a google search for hydroponics ull find em easy..or u could do a search for making your own carbon filter
gdluck!