You are buying this drone to capture steady 4K footage and build a kit that lasts you through years of shoots, not something you want to replace in six months. A good airframe with a reliable gimbal should serve you well for a long time if you treat it right.
Black Friday is coming up, which makes it a smart time to look for deals, but pay attention to release cycles. When a new model drops, last year's version usually gets marked down while keeping almost all the same core features.
Keep in mind that 0% intro APR is a deadline, not free money. If you still have a balance left when those 15 months run out, interest will kick in on what you owe.