I have a 383 stroker heads cam throttle body 1.6 rockers headers. i currently am using a mail order tune, i want a standalone. any suggestions on a good proven product would be appreciated.

 

Stock computer should be fine for making power and being reliable.
But if you insist on going stand alone you can always buy an AEM standalone, those are well proven, but cost alot
if you want you can use Mega squirt for under 1000$
If i was going to go stand alone i would use mega squirt, but with your setup it would be better to spend 500$ for a dyno tune with stock computer. IMO

 

I would use the stock computer, but thats just my opinion. Not sure on other good computers.