Heads for a Magnum Stroker Engine

Greeting from the Essex EnglandView attachment 1715844950
We have been bought an ATK Magnum stroker short block from Summit (delivery options are limited for us in the UK). What would be a good cam and head combination, the engine is going in a 1972 Dart which is used for drag racing only.
The existing engine is a very tired 340 (hydraulic flat tappet cam and iron heads) but before it gets a freshen up we want to gain a bit more knowledge on car set-up (cal-tracs are waiting) before spending money.
The other option we have is to stroke a 1990 318 block that we have to a 390 using a forged Scat kit and add a mechanical roller cam and victor series race heads.
Any opinions would be much appreciated from any of the forum members.
We are currently running 12.2 seconds at 108 mph and a bit of wheelspin on launch
Happy new year to you all and thanks in advance for any replies