Hey,

yeah that seems ok to me mate. you don't need a fan for intake you can have that passive, make your hole for intake at least as big as your exhaust, ideally a little bigger.

Make sure you get enough watts of cfl for your grow, from experience i'd say you need a minimum of 80watts of cfl per sq ft. (actual output, not equivalent!) tho the more light the better (i've seen 500w of cfl in a 2x2ft tent recently give great results), but you can start of with fewer and just add more when you start flowering.

Good luck!