what engine

i have an '89 crx that was given to me when my business bought a friends new software (no block, bad interior/exterior etc.). it was free, what can i say. my tuning garage specializes in radical customs, and i mean radical. i'm planin' on makin' this into a real power house. first i need a block. what should i be lookin' for? i'm tryin' to get as much power under that hood as i can. i mean as much as i can. a horsepower figure would be nice here. the vp of my company has a teg w/ a chevy small block in it puttin' out 350hp! i'm lookin' at a chevy big block right now (with some serious chassis/body modification of course). what do u guys think?