Currently I’m in the market looking for a good tune route for my car I’ve been strong on going with DIABLO for tuning but have 1 buddy that recommend another kind of tune, but I’m just looking for what will be best in a long run with the most potential, currently have CAI, Exhaust and I have high flow cat mid pipe and long tube headers on the way and also see me getting a cam in the near future.

 

the only good tuning I have found is for boosted engines. Normally aspirated engine tuning doesn't produce anything significant imo. a boosted 5.7 will blow the doors off all intake, exhaust, tuning mods combined.
tuners are $400 where I am. I haven't tried one on a na that is worth the cost.

 

You will need a custom tune for that cam. Possibly a phaser lock if it's big enough. Plenty of options out there from a variety of companies. Mainly depends on whether you want or can get locally a dyno tune. You can also get custom tunes via email.