Which hard-drive dock that works best with the new iMac 2011?

[seasurfer]

I am thinking of buying a 1Tb iMac 2011 i7. I don't want to waste money on the 2Tb one.

However, I may need more space in the future, I was seeing this hard-drive dock thing when I was browsing newegg, I never use one before, which one works best with iMac? Is there a thunderbolt one? Thanks.

 

[theSeb]

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TB docks are planned for this summer.