I have 16GB memory card and it is more than enough for me (that is ~500 frames).
I usually take 16~32 frames per object, plus one set of darks for the night,
Canon EOS utility (it came with your camera on CD) does the remote job (via USB) perfectly well, and you can store your images directly on the HD
However, I found the timer (
like one of those) is the best option, and it doesn't require lap or comp to do imaging.