SATA ports on the ASUS M4N78 PRO motherboard?

I am thinking of buying an ASUS M4N78 PRO motherboard. It has six
SATA ports. The manual says that ports five and six must be used in
RAID or AHCI mode. What types of drives can be used in AHCI mode?
What types of drives can NOT be used in AHCI mode?

It also says, "Due to chipset limitations, when you set any of the
SATA ports to RAID mode, all SATA ports run at RAID mode
simultaneously."

Does this mean that if you have two drives in a mirrored RAID, you
can not use any optical drive or any single had drives? Thank you
in advance for all replies.
--
Whenever I hear or think of the song "Great green gobs of greasy
grimey gopher guts" I imagine my cat saying; "That sounds REALLY,
REALLY good. I'll have some of that!"