I would just use dried birds eye chilli's as there are a lot of chilli's out there but some are very difficult to find.
I tend to use brandy rather than whiskey, although I have used whiskey. But if you remember the origins of this recipe, I doubt that when this was invented, whiskey was probably not around in the african/portuguese parts of the world. Also whiskey gives it a more coarse flavour, but again it all depends on individual taste, so why not try both and see what suits your palate best....
Marinating is always a personal thing. I am with you on this one, the longer you leave a marinade the better it gets....
I hope you enjoy the end result
