personally, i think you should get headers.
you will be able to run more timing, and with the 3.4 pulley you will have so much more flow up top.
the route i would take is...3.4 pulley, rockers, headers. ive seen those setups go 230-250 whp.
without headers you leave a lot of power out on the table for not too big a price.
then you can intercool down the line if you want moar powa.