Dynamic disk to RAID 0: Need help!

Hello,

Here's the situation:
- Vista Sp1
- 5 HDD
- 4 of the HDD are my storage (3 X 500 Gb + 1 X 1000 Gb)
- my storage is all shown as one unique virtual partition (dynamic disks expended)
- the space left at the moment is 900 Gb
- The disks are connected through SATA at the moment.
- I need to move my storage out of the PC for the following reasons:
>>>>>>>>>>> Not enough space left in my PC case
>>>>>>>>>>> Too much heat generated causes failures and hangs
>>>>>>>>>>> I cannot add anymore HDDs

My thoughts:
- Buy an external storage case that can house 4 or more HDDs
- Connect it to my PC through > ? (ethernet?, USB? FireWire? else?)

My problem:
- Is it possible to migrate a Dynamic disk set to RAID 0?
- I don't want to loose data. Is there a risk?
- I don't have an alternate disk to make a backup
- Is there a way to keep my configuration as Dynamic but connected externally, not SATA?

Thanks