Most motherboards come with a couple of SATA cables. The B450 Plus I linked comes with two. Any board you buy should have at least two. I think I've purchased a couple of micro ATX boards that only came with one, but I don't think I've bought ANY ATX board in years that didn't come with two.
If you go with the board you first linked, the B450 Gaming Plus, it also comes with two. No need to buy any.
Windows 10 will take between 20 and 40GB to install after you include any available updates. I recommend following this guide, exactly, when you are ready to install Windows.
If you are not purchasing a new Windows license, but are instead moving your current Windows 10 license to the new machine, I recommend you read and follow the suggestions explained in the following links, first, before you even shut down your current system if that system contains the Windows license you plan to transfer.