on the photopass website they have a selection of borders and such, just click on them and when you find one you like just click save as copy, this way you keep the original and the enhanced pic.
They can add stuff at the parks (in the photo centers) but I think you have to then purchase the enhanced pics there. I don't think you can add the enhanced photos to your photopass card, but I'm not 100% positive.
I love Target too! I got it from my friend who is a Target Shopping Queen.
I'm not positive but I don't see why you couldn't use the same card. But keep in mind that your October pictures will only be available online for 30 days.
the cards on only heavy weight paper though so they won't last forever.
test track had there own cards as of March (that's when we were there last). when you saw your picture on the screen, say screen #2, you will tell the CM standing there and he/she will insert a card into the wall, similar to the slots for the fastpasses. Then she will hand you that card.
You can add the number from that card to your online account.
We were able to add a really cool border to our Test Track pics via the photopass website.