Are ya gonna be hand quilting it? Machine quilting? Tying?
For any of them I make sure to have at least 3+ inches of batting & Backing sticking out on all 4 sides of the top.
Some long arm quilters (If you're going to have someone else do it) ask for at least 4-6 inches on all sides.
This varies and you should ask them first how much they want extra.
As for the binding either will work you don't add binding until you're done quilting/tying then you sew the edge of the binding even with the edge of your quilt fold it over to the back and stitch down. You can do this by hand or machine.