https://matrix.itasoftware.com/ is still my go to tool for checking fares. I think buy direct from the airline.

Thanksgiving week is a busy time and we tend to book that travel pretty early. We've been many times this week due to my kids school schedule. The frequent flyer tix from our airports get snapped up the day they are available. JetBlue has not posted their prices yet, so they are worth keeping an eye on. The general rule about buying 100-120 days out for best prices does not work for us for holiday weeks. If it were me, I'd buy the tickets as early as possible with the itinerary you want. Keep in mind, if you fly through STT, that the airport will be holiday busy on the weekends before and after Thanksgiving.

Cheers, RickG