Looks like a nice project. Just a couple of notes. The Fat16 library is much easier to work with but I have had some problems using it with the Stalker 168. I had to use the filelogger library on the 168 due to RAM overruns.
Also the FAT16 library is very fast so some SD cards have problems keeping up. I was using Dane Elec cards and they would not work which has been documented in the Fat16 readme file. I have been using Sandisk and Kingston cards successfully. The newer version of FAT16 is SDFAT and it contains some nice sketches which provides benchmark testing for SD cards.
I look forward to seeing more of your projects.