If you like Kingston, that's fine (I think they're a good company). But in looking at the Amazon UK site, I see that both the Samsung 860 Evo and the Crucial MX500 are priced below the Kingston for a 240/250GB SSD. The Kingston has a 3-year warranty, the Crucial has a 5-year warranty. The Samsung warranty isn't listed on the Amazon page but here in the US, it's 5 years. The Kingston and Crucial have rated endurance of 100TBW (terabytes written), the Samsung is 150TBW. For most people, even a 100 TBW SSD placed in a 2012 MBP will last far longer than the computer. I haven't looked at the Kingston performance specs, but I'm pretty sure it will be slower than either the Samsung or the Crucial and if it is faster, you won't be able to notice the difference in speed (not a knock on Kingston, but with both the Samsung and Crucial, they're both pressing the limits of what can be done with the SATA3 technology).
You should change the HDD cable when you change the SSD - the cable has been known to be problematical and it's not uncommon for the cable to work fine with the HDD only to have problems with a SSD.