Opening your closet and actually finding what you need without digging through piles changes your whole morning. Building a custom system takes a few weeks from design to installation, but January is the best time to book because storage companies run their biggest clearance discounts right after the holidays.
Don't just take the first price you get. Bring in at least two different local designers or closet companies to measure your space and bid on the exact same layout so you can compare labor and material costs side by side.
That 0% window is a hard deadline, not free money. If you still have a balance left when the 18 months run out, interest will kick in on the original amount from day one, wiping out your January savings.