Can't give you any advice on the highpoint, but can give my two cents on Adaptec's offerings. AFAIK they are only a little bit more expensive, but at the time of purchase boasted slightly higher throughput. Bear in mind that unless you have 6Gbps SAS or SATA SSDs, you won't saturate the bandwidth of SATA 3Gbps. You will also lose TRIM.
They will add a good minute to your boot time, so if you need to switch the computer off frequently (more than once per day), it will be annoying, especially when you lose a drive and have to rebuild arrays. TTL did a 12 drive server earlier this year.
Additionally, if you value your data integrity, buy a battery back up unit, which (though expensive), will preserve the cache in the event of a power failiure or hardware lockup. Using a BBU meant that even powercuts during intensive periods didn't lead to corruption.
Make sure the motherboard supports booting to a PCIe card (Crosshair IV does not for example). In my experience scan are the best people to talk to, as they tend to know at least the rudiments of them, and can provide some valuable help if breasts become upwardly inclined.
