Have you ever successfully connected any SATA HDD to the motherboard and it is recognized in the BIOS? I suspect the problem may be in the nvidia chipset. The manual is confusing as MSI mixes the terms RAID and IDE on the same connectors.
I have two SATA drives connected at the moment with the AHCI configuration and they work fine. The main drive is a SATA VelociRaptor from WD and I bought the Intel SSD to replace it.
The difference is that both my current SATA drives are SATA 2, where the Intell SSD is SATA 3. The spec though say that it is backward compatible to SATA 2.
I've connected my 520 series SSD to Intel and Gigabyte motherboards that supported SATA2 and currently a Gigabyte motherboard that supports SATA3. All three motherboards were using Intel chipsets set to AHCI and there was never a problem with the SSD being detected by the BIOS.
In theory you should be able to connected the SSD to the same SATA port that the WD currently uses and it should work. If it's not, try a different SATA cable, maybe the one packed with the SSD if it came with one. If a different SATA cable doesn't work. I'm still thinking it's the nvidia chipset that's the problem. Maybe a new motherboard?
My existing cables work fine with either of my current HDDs. There are SATA 3 cables and neither of them works with the Intel SSD.
I like your idea, but I am not planning to upgrade the motherboard or CPU or RAM at this stage. If I can not make it work I will just return the SSD.
I have connected the HDD with the cable that is in the box and it still does not work. I tested the cable with my old SDD and it works fine.
Any other ideas?