DV7 triple boot w/3 different storage devices?

I have a DV7 quad edition that currently has a 500gb HDD with Windows 7 installed and a 120gb hdd installed in the second bay. After I finally figured out that the bios doesn't offer the ability to boot directly to anything but the first HDD and the optical drive I've gotten curious as to using a chain-loading setup to potentially run a third storage device for a third OS, likely Linux of some flavor.

I didn't opt for the OTA HD tuner and thus have an unused mini PCI-E slot that I'm thinking about filling with a SSD. Has anyone tried this or anything like it? I can't think of any obvious difficulties I will come across given that the BIOS also doesn't seem to have the built in ability to boot via PCI-E or over ESATA for that matter but I don't see why chain-loading won't solve this problem - assuming the mini PCI-E slot is accessible just after POST is complete.

 

As for the empty mini-PCIe slot, it is whitelisted and therefore cannot run anything except approved wifi cards. However, the TV tuner card slot is actually a USB slot.

Even with a chainloader like grub, you won't be able to boot off of an eSATA device because it requires a driver.

Your best bet is to partition the C drive for you OS's of choice.