Arduino, file systems, SD cards and copying

In my thinking I have been leaning towards the SPI & hardware serial connection in tandem. I wonder how well they will talk to one another.

The files would probably be biggish, in comparison. 3, 4 megs maybe. And there might be more than one.

Oh Snap. This is gonna get messy. Is the difficulty with the vdip module just a simple 'does not show up' issue?