There is scrabble tile letter fabric available. I did a Google search using those words and came up with several hits. However, as my friend found, when she made her quilt, the words that she could make were limited by the amount and variety of letters on the fabric panel. I believe her letter panel could be cut into 2 1/2 inch squares. m My friend's quilt is absolutely beautiful! She used bright scrappy 2 1/2 inch squares as the background and because the letter squares were all the same colour, they really stood out.
I am wondering if Spoonflower would be a better choice and if you could specify how many of each letter you wanted. Of course, you would have to plan out all your words first.