If you are local to Warwick, NY. I got to Breeframeworks on South Street above Tuscan Cafe.
Online, I use pictureframes.com for slightly ornate frames, like the one pictured above that comes in different colors. This collection in this link all have a rabbet depth of 1 1/4”.
For a more contemporary look, you can use these floater frames, It all depends upon the look you are going for in your home.
Your local Michaels: You might be able to order one there in the size you want and put it in the frame yourselves. They do have a good selection there. You just need to make sure the rabbet depth is at least 1 1/4” – 1 1/2” (that measurement is the depth of the canvas, you need that otherwise the frame sticks out away from the wall too much and you can see behind it because the canvas thickness is 1.5” – the 1/4” is no big deal)
There are also lots of custom choices available on Etsy. Try to enjoy the process! 😉