BELKIN SATA 2 EXPRESSCARD F5U239 with the SILICON IMAGE SIL3132 card
So, it may be the fastest to go with your mybook with esata, it is fast, but has many shortcomings.
To begin with, you can not boot your laptop from this card, you can if you install a software boot loader but the hardware is not bootable.
This card worked fine with a sata port multiplier by silicon image, unlike many other sata controllers.
2 LEDs are there showing disk activity, but remember that although they say it gives you a 3MBit connection to the hard drive, the maximum of the connection is much less having the expresscard bus as a bottelneck, even worse, both hard drives will have to share that expresscard bus !
All in all i am happy with the product if it were not for the boot issue.