Welcome to the Forum. My Spirit is shaft drive, so I'm not too familiar with chains. Get two more thread starts and then you will be able to post in the tech section. Or, ask the moderators to move this to the technical section.
Yes, spend the extra few bucks. Have you checked eBay for the sprockets? JT is a good one. D.I.D o-ring or x-ring chain. I got the whole set for just over $100 on eBay.Go with the 38 if you still can. Best and cheapest upgrade I have done yet. Completely different bike. Many here will agree with this. Not worth the money saving.