Open Question: Can you use Multiple RAID Cards?

I am building myself another new computer, and having experienced HDD failures, I want to protect myself against them. At current, I have 2x 2TB drives in my PC. 1 is partitioned up for the OS and DATA, and the other drive is to store backups. However, I would like to use RAID in my new computer. This is the RAID layout I am looking for: Drives 1 & 2 (2x 1TB Drives, SATA) in RAID1 for the OS. Drives 3,4 & 5 (3x 2TB Drives, SATA) in RAID5 for my DATA. Drives 6 & 7 (2x 2TB Drives, SATA) in RAID1 for Backups. Now, I had a quick look but couldn't see any 7 port raid cards that would do this. Is this possible, any cards you would recommend? Or, can I use more than one RAID card in my PC. Say, a 5-port one and then a 2-port one? Thanks.