I would say that's extremely ambitious (trying to make a reversible quilt). Trying to keep everything aligned is going to take meticulous attention to detail when basting - constant checking front and back as you baste. I would suggest you do a web search to see if you can find any video tips on how to align and maintain alignment.
Also realize normally you want the backing 4 inches bigger on all sides than the quilt top, to allow for distortion that results from quilting. You would probably want to add sacrificial borders to the one you're using as the back, so you can trim it away after quilting.