Promise SATA150 TX4
The TX4 has already been available for a good while. Together with Silicon Image, Promise can be considered a forerunner in the market for "smaller" controllers for Serial ATA.
Although the SATA150 TX4 only has a 32 bit PCI interface, it can work with 66 MHz rather than just the usual 33 MHz, so there is no bottleneck even at full capacity with four up-to-date hard drives.
With a two year manufacturer's warranty you're good to go, but unfortunately no ATAPI devices are supported.
As an alternative, the Promise product line offers the SATA150 TX2Plus, which offers two Serial ATA ports and an UltraATA/133 port.