[CentOS] add on sata card relabeling drives, installation

Hi all.

I have a new server and am playing with the installation. (centos 6). My 
onboard sata card has 6 drives attached to it,
yet the server has 8 bays. I bought a sata controller card (adaptec) and 
added it to the mix, adding two more drives.

Everything works and all is accessible, but there is one annoying issue.

When installing with anaconda, the 2 drives located on the add-on sata 
card are being listed as sda and sdb instead of going
to the back of the line.

I would rather my a and b drives be the 0 and 1 sata ports of the 
onboard controller, but it seems the add-on is taking priority.

My only thought is to install without the 2 drives connected and then 
add them afterwords.
But again, that makes no sense to have to do it that way.

Is this just normal for the add on sata cards?
If I add the drives to the system after I install it all, will linux 
barf on it and change the drive letters?

I do not want my raid 1 mirror OS to be on sdc, sdd, and sde....it just 
looks weird.


thanks