Need external Mac HD advice

I currently own a 24" iMac w/250gb drive. I was in desperate need for a backup drive to migrate data from my PC to Mac so I bought a WD 250gb USB 2.0 drive. It was a dog so I returned it today and ordered a 500gb Mybook Pro from B&H for $172 and it will give me the Firewire 800 port I need for my iMac and the USB 2.0 for my PC.

With the new iMacs coming out in another few months there is a possibility that I might rotate this computer to my sister and purchase one of the newer models which will ship with a eSata port which at 3000Mbits/s is a big performance jump from the 800Mbits/s that firewire 800 offers.

Here's where I am running into issues- I can find drives with USB & eSata and drives with USB/FW400/FW800, but I can't find any drives that will give me USB/FW/and eSata. I'd hate to not swap machines at be stuck at 400Mbits/s USB or upgrade and be stuck at 800Mbits/s FW800 v. the 3000Mbits/sec from firewire.

Is there an alternative that I am missing?

MiniStack V3.

http://www.g-technology.com/Product​s/G-DRIVEQ.cfm

i have a powerbook, and was going to buy a product from this company but found a product that suited my needs better, this company gets very good reviews in the mac magazines..

hope this helps.

rich,

don't get too caught up with the speeds of the ports, it is theoretical, and the internal drives that come in those cases rarely are able to keep up with the max speed of the ports. i bet you won't be able to tell a difference from the fw800 and esata port. and keep in mind the esata port drives will be more expensive when they come out.