mobo you could pretty much half the price and get a no thrills 1155 board
cpu - i3 - lower end i5's
SSD a 60GB intel or 64GB samsung 830 will be nice for speed and reliability
love the RAID card, Adaptec are great cards
8GB of RAM is all you should need if you you want to use ZFS, RAID Z such as freeNAS.. lf you go this route you can replace the RAID card with a SATA card if you need more ports as linux software RAID is just awesome and eliminates the need for expensive RAID cards..
Hardware RAID tends to be expensive and clunky. I recognize quite a few advantages in ZFS on Solaris/FreeBSD, and Linux MD RAID:
Performance. In many cases they are as fast as hardware RAID, and sometimes faster because the OS is aware of the RAID layout and can optimize I/O patterns for it. Indeed, even the most compute intensive RAID5 or 6 parity calculations take negligible CPU time on a modern processor. For a concrete example, Linux 2.6.32 on a Phenom II X4 945 3.0GHz computes RAID6 parity at close to 8 GB/s on a single core (check dmesg: "raid6: using algorithm sse2x4 (7976 MB/s)"). So achieving a throughput of 500 MB/s on a Linux MD raid6 array requires spending less than 1.5% CPU time computing parity. Now regarding the optimized I/O patterns, here is an interesting anecdote: one of the steps that Youtube took in its early days to scale their infrastructure up was to switch from hardware RAID to software RAID on their database server. They noticed a 20-30% increase in I/O throughput. Watch Seattle Conference on Scalability: YouTube Scalability @ 34'50".
Scalability. ZFS and Linux MD RAID allow building arrays across multiple disk controllers, or multiple SAN devices, alleviating throughput bottlenecks that can arise on PCIe links, or GbE links. Whereas hardware RAID is restricted to a single controller, with no room for expansion.
Reliability. No hardware RAID = one less hardware component that can fail.
Ease of recoverability. The data can be recovered by putting the disks in any server. There is no reliance on a particular model of RAID controller.
Flexibility. It is possible to create arrays on any disk on any type of controller in the system, or to move disks from one controller to another.
Ease of administration. There is only one software interface to learn: zpool(1M) or mdadm(8). No need to install proprietary vendor tools, or to reboot into BIOSes to manage arrays.
Cost. Obviously cheaper since there is no hardware RAID controller to buy