Smart lighting should last a decade. You want bulbs that don't flicker or lose connection every time the Wi-Fi blinks. Buying a starter kit and expanding it during big sales is better than mixing cheap brands that won't talk to each other later.
Wait for Prime Day or late November. Last year's bridge models often go on deep discount when the newest sensors drop. They usually work just as well for a standard living room and save you a decent chunk of cash.
The 0% rate is a temporary window, not free money. If you still have a balance after 18 months, the standard interest rate kicks in on the remaining amount and makes your lighting setup much more expensive.