Don't know your situation down there as far as cost, but, I would REALLY look at this website, for a ballpark figure of what you are running, and, if what you are trying to do might better be accomplished by a motherboard-cpu combo upgrade?
http://www.cpubenchmark.net/
http://www.cpubenchmark.net/cpu_value_available.html
That said, I did something close to what you are talking about. I have a Supermicro Dual Xeon 2.8 Ghz that I bought about 10 years ago. The PCI-X slots on that board are advertised
as near 500 MB/sec capable. In reality, they are doing 200 MB/sec with 3 Vertex Turbos, and
a 9550s-4.
The problem seems to be the cards are designed for single channel capability consistent with SATA drives in about 2005, not SSD's now. None of the current PCI-X cards are any faster then the one I'm using, and some are slower. There just isn't anything designed to take real advantage of the SSD throughput. the 9550 seems to be the best of show in this area, but, it really is going to give you little more then what a single SSD will give you on a SATA II card.
Next: when we went to upgrade the server, finding all the right drivers for all the different components, and really, there weren't that many, became a royal pain, and, IIRC, finding the right driver for the 9550 was our real problem, and, finding a ATI driver was another problem, due to using a 4670, and the legacy driver wasn't anywhere to be found, for AGP.
Finally, we ended up going to Windows 7 Ultimate for the install, since finding drivers for 2003 Server, my favorite operating system, didn't work, and, trim was a major factor as well.
Does it work? Yes, it's pretty snappy. In retrospect, the 9550 was around 100 dollars.
The SSD's 450 dollars. All will be forward compatible, but, I could have tripled my processor power by upgrading the motherboard, cpu and ram, and I suspect that would have
allowed a better chance of the bus working at the speeds you are after.
Here is the atto result from the Supermicro server:
Here are the results from my computers onboard, two X-25M's: