Building a n100 server

Hello ! I want to build a n100 server but, the motherboard come with only 1 sata port.

I've seen this kind of M2 adapter, or pcie one (more expensive)

Do you think one or the other will be great to make some RAID ? No speed down compared to sata on the motherboard ?

I'll connect 2x6TO 3.5" nas hard drive, and maybe a 2.5" SSD. Maybe 4x6TO later but not for now

Thanks in advance