Storage options

[Old Geezer]

Another nooby question.
My current W7 PC will donate a couple or three parts for the new build in my signature. These will be the Samsung 860 evo 500GH SSD, an LG optical drive, and a WD MyPassport 1TB usb external drive.
W7 resides on the SSD atm, but I'm planning to format it then replace it with W10. I'm now thinking of adding another 1TB internal HDD/SSD for storage, and using the external just for back up.
So I'm wondering what to go for? The MB also has M.2 slots, so that is a possibility too.
Your thoughts please?
Cheers, Trev.
Silver surfing gamer, FSX,TS2020, Cities:Skylines. Reactions too slow for PUBG

 

[Old Geezer]

Anybody please?

 

[Old Geezer]

Thanks for your input, the blurb from the motherboard as follows;-
1x M.2 (M-Key, PCIe 3.0 x4 with max. 32 Gbit/s, Sizes 2242 to 2280)
1x M.2 (M-Key, SATA6G, sizes 2242 to 2280)

 

[Old Geezer]

Many thanks,, The second M.2 does disable the SATA port as you thought, I think I'll stick with another SSD. I'll have a look at the Corsair, Thanks again
Cheers, Trev.