External Hard drive for editing. possible raid.

I have been researching all day but I want an opinion from the Mac community on this. I own a 15'' MBP Core Duo II 2.0 GHZ with 3 Gigs of ram. (I think I maxed it out) On Leopard. I'm running final cut studio 2.

I wanted to run an external HD setup to do my editing on. Obviously firewire 800. But I was interested in eSata also. Firewire Depot makes a SATA port for the MBP and i can have the claimed 3.0 Gbp/s speed. Will the expresscard/34 allow me to do this in my machine? I would really love swapable drives.

http://fwdepot.com/thestore/product_info.php/products_id/1753

(eSata thru express card)

Anybody have some really sweet setups I could do for on or about 400 dollars? I would love the ability to upgrade the setup later. But I want to run at least 2 drives. I eventually would want to be able to edit HD but I'm working in DV tapes for now. Please, any input would be great.