If I change to Linux are there any obvious issues I may run into that anyone knows of?
Your raid controllers will need Linux drivers - many do, just make sure.
Also - your current filesystem is probably NTFS. Linux has read-only support for NTFS, but cannot write AFAIK. If you have significant data on the drives already, this may be the biggest hurdle for you. I made a similar switch from Windows 2003 Server to Linux, and I copied data to machines all over my home network so I could reformat the RAID array.
I use NFS for all of my mounts on the PhotoBridge, but the posters here are correct - SMB is pretty easy to set up under Linux, and for most media performs adequately.