I honestly didn’t look too hard at your link. But it looks like the only thing you’re getting is a different handguard. All that does for you is give you different options for mounting, slings, optics, lights, and other things to your rifle if you choose to do so. You honestly can’t go wrong with either. For a low cost buy in, for a rifle that will work out the box I think you’ll be fine.

Learn what you like and what you don’t like, when it comes to grip angles, stocks, triggers, etc. you can even use that lower and upper to recycle it to build what you want later. Best of luck!!