Zegg, buddy, seriously consider the add in card. I have a whole bunch of systems in my business. I soup them all up because I am stupid and like to waste money (ouch it hurts to say that). Anyway, I have RAID 1 running on Intel ICH7R, RAID 1 running on an nvidia 650i, RAID 10 running on ICH7R, Raid 10 running on ICH9R, RAID 0 on a nvidia 780i, RAID 5 on a ICH9R and RAID 5 on a highpoint rocketraid3510. The RAID 5 on the highpoint card smokes them all by a LARGE margin. I get hd tach burst speed over 1100mb/s with 4 raptors on the highpoint card. I had to run the test a few times before I actually believed it. It so far outperformed my other solutions, I thought something was wrong.
The cool thing about the add in card (and a few other add in cards I have had over time) is that you can take them from one computer to another. With the integrated, I was always afraid of moving my array from one mobo to another. There is no guarentee that even the same RAID chip will support the same array between two motherboards. I have sucessfully moven an array from a 680i to a 780i, but I wouldn't count on it.
Also, the speed of an add in card is far superior to that of an integrated controller. At least that is true for the hardware based cards as opposed to the software based cards. If you can afford it, go the add in card route.
If you can't, then I would have to recommend the ICH9R southbridge chipset from intel. It doesn't matter what board you like has it, it runs the same regardless. It is very compatable, and so far, very reliable. IMHO, it is faster than the 780i nvidia equivalent.