When I purchased my MP10, I was very displeased with the handguard. It had a lot of movement and was not reliable for a firm shooting grip. My first "non-bench" shot groups were horrible in comparison to shooting other rifles (and I'm a horrible shot to start with .. so it was just sloppy horrible). I exchanged the handguard with a Magpul that I had spare, and my standing shot accuracy was back to normal.
Both upgrades are good choices for your rifle, and can add benefical comfort and convenience to its use. You should assess your toolbox (both in tools and experience) and decide which you want to take on first, as both installs will have unique issues (and additional costs other than just the part) that will crop up and require the right tools and the right skillset to overcome. If you are new to AR platforms, installing the prs rifle stock is probably a good first project after replacing the grip. As you could probably tell above, I'm no fan of the quality of the stock handguard, and would change that first ... btw, I threw that original handguard in the trash ... wasn't in the least bit interested in keeping it as a spare.