A good 34-inch curved ultrawide replaces two messy screens with one clean view. It should last you at least five years, so buy the panel specs you actually need now instead of a cheap stopgap you will want to replace in a year.
New monitor lineups usually launch in late spring. That makes early summer the sweet spot to grab last year's model at a discount, often dropping a $750 price tag down significantly before stock clears out.
Remember that a 0% intro period is a strict deadline, not free money. If you still have a balance after 18 months, regular interest applies to whatever is left, which wipes out the savings you got on the purchase.