What is your goal? Do you want to spend some $$, and about how much? I would go with heads first, if it is in budget. Keep the compression up there though, or it will cost you a lot of what the heads gain. You can run the lash tighter, which may provide a decent return on investment! Try the intakes first. (.016?)
On the heads, the sidewinders by trick flow may offer some advantages over the other aluminum heads. Keep an eye out for some results , hopefully accurate back to back tests against other aluminum heads.
Finally, fine tuning everything in the car may pay some dividends as well. Leave no stone unturned, if you haven't already. Guys here love to help,,,,,