For the record-to-SD requirement...
(That shield also gives you a RTC, which might be useful)
With ANY use of an SD card, as far as I am aware, you need to design carefully so that there is provision to write buffers to the card before it is removed.... Like the "safe to remove" procedure with thumb-drives and Windows (and other OSs? "Mount"/"dismount")
If you are interested in the SD side of your design question, perhaps a separate thread would be a good idea? And if you do that, remember that you can edit your first post in THIS thread to avoid "thread fray".