As JayT said, you can use what ever you want in the marinade/rub but you should only use dried chillis when the meat is ready to go into the deydrator, and it would be better if is ground pretty fine (IMO).
Don't Sprinkle dried herbs on the meat before it gets dried cause you will end up with all this chunky dried horrible tasting crap all over the meat....Just think to yourself......"will this ingredient still taste good on the meat after being dried at medium temps for long periods"? Most of the time the answer is no...
Have fun mate