Trick Flow Stage 1 is a mere $140 plus shipping from Summit. It has good street manners too. As far as clearance, you could check the clearance you have with your existing cam using and temporarily bolting (not torquing) on the heads (and gasket) you will use. Place putty or play doh on piston before bolting on head and gasket. Then turn the crank a couple of times, remove the head and check thickness/clearance.
My pistons are between 3-5 thousandths above deck, using a .39 inch gasket and Winsdor Jr. heads cut .020 (1.94 intake /1.60 exhaust), I surprisingly still have lots of clearance. I run 1.6 rockers and stage 1 cam (.499/.512 lift).
I actually first purchased the Stage 2 cam, but chickened out and sent it back for the Stage 1 and I am glad I did as the Stage 1 makes good vacuum (i.e. no problem with power brakes) and has an impressive power band. I took one buddy for a ride and his comment was "Whoa! this is one stout 351 !" I informed him that it is just a little 302.