Hi there,
So, I wanted to write a good response down for you since you had indicated that you've looked around and couldn't find a lot of information about this kind of stuff. I wanted to be able to hopefully teach you a few things as I make a recommendation so you can do some more research later if you wanted. So here we go.
To answer one of the first things that you mentioned,
any SSD will be faster than a 5400 RPM HDD. SSDs are much quicker because of their ability to do much more IOPS (Inputs/Outputs Per Second). This being said, you won't have to worry about some SSDs being slower because they have a better longevity than others.
Now to answer your main question about longevity. SSDs have come a long way since they were first on the market. These days, longevity and reliability are not something that you'd have to worry about shopping for, especially in the 5 year range. Unless you're looking to buy for like 8+ years, its not something that you would
necessarily need to worry about. The only other factor that affects this is how often you are writing to the SSD.
The reasons an SSD fails over time is that each cell can only be
written to a certain amount of times. Your PC can read from the cells an unlimited number of times without degrading the drive. So, unless you are going to be using the SSD for mass storage that is constantly being overwritten (like video camera feeds, etc), you shouldn't have to worry.
If you are a regular user who needs a drive for an operating system, and normal usage, I would recommend buying a Samsung drive. Samsung tends to source better NAND flash chips, which gives there drives a better lifespan. The two things you need to look for in an SSD as far as longevity goes are the following:
- MTBF (Mean-Time Before Failure) - the higher the better
- TBW (Terrabytes Written) - higher is better (always higher with bigger capacity)
Lastly, make sure you're still backing your data up periodically, just to ensure that everything is saved in case the SSD or even a different HDD goes down, you never know what could happen. Keep in mind you can re-use your old HDD as an external drive if you get an enclosure for it!
So the TL;DR is this...
Most SSDs these days are good on reliability. If its something that you're worried about though, I recommend Samsung drives, like the 860 EVO series linked below:
https://www.newegg.com/samsung-860-evo-series-1tb/p/N82E16820147673?Description=samsung SSD&cm_re=samsung_SSD--20-147-673--Product
Let me know if you have any more questions, and happy researching! hope this helps