You may have already gotten started on this, but I personally found the best method to switch Vita and memory card was as such:
- Turn off original vita, remove 32 GB card, turn vita back on. When it boots, deactivate it through the PSN menu, and format it after that.
- Turn on new vita, activate it through PSN menu, turn it off. Put in old 32 GB card, turn back on. Congrats, your new vita now has all the games/stuff of your old vita.
- Now to switch cards, download contend manager assistant on PC or mac and set up your folders. Once that is set up, plug in your vita via usb to your PC/mac.
- Launch content manager on vita, press "copy to whatever" or something, and select Vita to PC/mac. Now you can check mark all your games and copy to your computer. Keep in mind you have to do Vita games (under applications I think), PSP games and PSone games all separately. This will take a while, but much faster than doing it to PS3. Also keep in mind that you may have to move PSP/PSone save data separately, don't remember.
- After the transfer finishes, turn off vita, take out 32 GB, plug in 64 GB. Open content manager on vita again, and select the other option (Computer to Vita transfer) and transfer all your stuff back.
This will all take a long time, but it will fully transfer everything, including most game saves and all patches and updates for games (e.g. SAO will be already updated and ready to go)
Hope that helps some!