Mac Pro -> new iMac - how to boot?

So I'm selling my 1,1 Mac Pro, but keeping my 2.5" Intel SSD. I know we don't have much clarity about the HDD+SSD option (but the guesses suggest it's a blade PCI interface like the MBAs). I'm not up for paying Apple $600 for their SSD.

My question is, what's the best way to interface the 2.5" SATA SSD to boot from? Are there Thunderbolt enclosures yet? I'm guessing FW800's antiquity negates the advantages of an SSD? Maybe Thunderbolt-to-e-sata adapters?

Input/suggestions appreciated! I wasn't sure whether to call this an upgrade or downgrade or what so I just used the ->.

one more question

Does anyone know if the stand for the new 27" iMacs can come off? I'm planning to carry it overseas with me in a suitcase (as I carefully have done with my Mac Pro and 30" Dell monitor) but I think the stand will have to come off for that to work.

Thanks - all helpful! The previous generation SSD never had the option to be installed in conjunction with a HDD, right?

I forgot my third option - opti-bay or whatever to put an SSD in place of the optical drive. I've done this on my MBP and don't miss the optical drive often at all. Of course, this isn't easy job to swap out myself.

Hmm so I hadn't realized there was a BTO dual HDD+SSD option with the last generation iMac. Guess I need to research that. Much of what I've been reading suggests against doing this on your own. I'm pretty brave with opening Macs (and learned a difficult lesson tearing a paper-thin ribbon in my uMBP) but the iMac might be out of my league. $600 for an SSD (esp when I already have one) is hard to envision, though.