I've done some similar work to what you are describing. I have adhered the canvas or linen sheet to either hardboard or foam board. Then either frame or mat & frame (similar to watercolor). Because I use acrylics, I do not use glass. I always use either a ph neutral glue or tape to mount the final painting (which is sealed as well).
Here's a link to one of my paintings on my website, showing the 3 options.