Just bought a HP P400 Smart Array Controller with backup battery off Ebay for £40, see if it does what I want, if not, sure I'll get my money back on it.
Yep, that is a nice price for the unit. You may want to check what condition the battery is in when you get it.
As the P400 is a SAS controller (not a native SATA controller) you will need to get the correct cables to link the drives to it. I believe the unit uses the SFF-8484 connectors so you will need two sets of SFF-8484 -> 4x sata cables which can be had cheaply on ebay.
The controller is PCIe 1.0(a ??) so supports 2GB/s over 8 drives but it only supports SATA I (150MB/s). This should be fine for all mechanical hard drives but a little slow for SSDs. The controller also seems only to support up to 1TB drives by the spec sheet
here. I am sure someone can confirm this though.
LSI 1068 based controllers are usually worth a punt. The 3081E-R, Dell 6ir or the IBM BR10 or various others. These units use the newer SFF8087 -> 4x SATA cables (apart from the Dell which still uses the SFF-848), certainly support 2TB drives (I have had some hanging off my old ones) and work very well. The LSI 1068 chipset supports SATA II, specs
here.
If you want to move to the current generation then you could do worse than look at the LSI 9211 which is a 6Gb/s per channel (x8 channels, one for each device) and is PCIe 2.0 compliant meaning it cat push upto 4GB/s to the motherboard. Just as a tip, the IBM M1015 is based on the LSI 2008 SAS chipset (like the LSI 9211) and can sometimes be found on ebay and a certain on-line book shop for silly prices. If you then reflash the cards with the LSI 2008 firmware you end up with what is essentially a 9211. The caveat is that the flash software does not work on all motherboards (google flashing IBM M1015 for lots of advice). At worst the M1015 is still a nice SAS controller. There is one in the US selling for around US$70 on that book shop. I got two for just over US$100 each and have them in my ESXi 20 drive server.
Having a google for 'Home Server' should bring up a few sites with info on stuff like this if you want to dig a bit further.
RB