Best Options for Internal hard drive and RAM?

Hi there! I am totally new to this but I have taken a look at the videos and some guides for upgrading the hard drive and RAM and it doesn't seem to be overly complicated.

I want to upgrade the hard drive and RAM and I have a budget - no greater than $400. For the RAM, I have found this but Apple claims the MBP can only support up to 8GB RAM though the Youtube video showed the 16GB RAM working fine.

As for the hard drive, I have been looking into Solid State Hybrid Drives as from what I know they're not as expensive as SSDs but provide better performance than normal hard drives. I have came across this though the RPM is 5200RPM.

I generally want the best value. The RAM at 16GB seems a lot to me and I am not sure if 8GB would be a better answer. I only use the computer for school work and no photo/video editing and I do have many tabs in Chrome open (some of which are youtube videos) and multiple word, powerpoint, excel windows open at the same time. So if 16GB of RAM will mean noticeable increased performance then I'm all in.

As for the hard drive, I am unsure if that is the best option.

Thanks for any future help!