As I said last week, RIFTS has plenty of inspiration out there. One of the best, post-RIFTS, is Vampire Hunter D: Bloodlust.
Vampires, mutants, high-tech, specialized anti-undead techniques and tools, silver-as-anti-vampire, cross-as-universal-repellent, post-apocalypse w/ space travel. This is regarded as a RIFTS movie for very obvious reasons.
Go on, watch the film. Here, or elsewhere, or whatever, just watch it. Now imagine this occurring as a campaign in Vampire territory in North America. You can see clearly how this would work in RIFTS, can't you?
No, no rules or mechanics conversion will be done here; you're on your own, and by now you should be able to handle that task without me holding your hand.