I have quite some experience with SMD soldering, but I would like to confirm that (should you decided to solder wires to the serial port) you should be extreemly carefull as the contacts let go very easy.
Therefore I think the suggestion to use pins instead of soldering is a very good one. Ground is easy to find on different places. Personally I have used an external 1.8V powersupply with a current limiter to feed the serial converter, to connect as little wires to the Kindle as possible.
I used a simpler converter, but I had no luck, as the level converter did not work well. So I would strongly advise to use the suggested converter (which is on order for me now)...
To the initiator for this thread:
