I know very little when it comes to the General's motors and parts, being a blue oval guy myself but some of this stuff goes for both and the Mopar guys too.
AFR makes the most popular heads going, their marketing is above all their competition. When I built my 351W the two main competitors were Edelbrock and Twisted Wedge and I chose the Edelbrocks based on personal recomendations from a raceing engine builder. He said the Edelbrocks have a higher quality of the factory casting than the TFS units, although the angled valves do have a higher potential after some work. You might want to look at Canfield or Brodix heads too, they offer plenty of performance for the relatively mild output you are seeking.
Frankly if you are looking for only 400 fwhp from a 383 then the AFRs (I assume you want 185s right) may be too much for your cam. Getting 1.25fwhp per cubic inch with aftermarket aluminum heads and a roller cam/rocker combo si child's play these days.
On another subject, why not drop and LS1 in there, even if you have to replace the electronics it isn't THAT big of a hurdle. And those LS1 motors are simply awesome, there's tons of potential in them, and thats coming from a fan of Henry...LOL!