Install OS on RAID1 thanks to dual SATA board?

[Thatoo]

Hello,

Let's say I buy this list
ROCKPro64 4GB Single Board Computer
ROCKPro64 12V 5A EU POWER SUPPLY
ROCKPro64 PCI-e to Dual SATA-II Interface Card
ROCKPro64 Metal Desktop/NAS Casing
Fan for ROCKPro64 Metal Desktop/NAS casing

16GB CLASS10 MICROSD CARD

and two SSD drive

How can I install armbian on a RAID1 of these two drives?
I understood that these two drives can't boot. I need to flash the SDcard with armbian installer (https://www.armbian.com/rockpro64/) and I'll always have to boot from SDcard.

However, I think it's better to install and use the system from SSD because it's safer (Sdcard don't last long) and SSD have more capacity and they would be in RAID1 (so safer also)

So, how can I boot from SDcard but have armbian system installed on SATA and specifically on RAID1 (2 SSD)?

Do you know tutorials (text or video) explaining how to reach to this situation?
- How to create RAID1 for 2 SATA drive connected to ROCKPro64 through the ROCKPro64 PCI-e to Dual SATA-II Interface Card?
- How to install armbian system to this RAID1 from the micro SDcard plugged in the ROCKPro64?

Now a side question : as we are talking about SATA-II, I guess the speed of SSD doesn't really matter as it is SATA-II which will limit the speed?