You've spent so much time in Thailand this year, even a multiple-entry tourist visa leaves you at risk of being denied entry. A tourist is a tourist, regardless of you having a visa or not, and you're already near where they start interrogating people entering as a tourist.
The non-O visa would not have any risk of being denied entry. You will get a 90-day entry stamp when you arrive, and if you want to leave and return you can purchase a re-entry stamp at the airport on your way out. It's 1000 baht for a single entry, or 3800 for multiple entry. If you have them do the photo for you, it's
*********
baht.
A re-entry permit does NOT give you extra time. It just means the stamp in your passport is not cancelled when you leave Thailand. So if you arrived and get a 90 day stamp letting you stay until November 15th, then leave with a re-entry permit and come back 2 weeks later, you'll be stamped back in with the same stamp until November 15th.