Dream RAID

I'm about to provision out a mac pro to be a RAID server

currently we have a few NAS' and Promise thunderbolt RAIDs

We are looking to setup a quick front end storage RAID for our workflow and then a back-end storage array to house images, apps, profiles for a domain that we will be rolling out in a few months.

I'm wondering if there are any recommendations for RAID cards or chassis from some experienced admins here

I was thinking of a mini-SAS raid card because those cables are longer allowing us more flexibility in our rack and placement of eventual RAIDs