Get a card based on the access to internet you have. If you are pretty much constantly in contact with fast wifi 24/7 8GB will be fine as you can just download and delete as you play.
I have 16GB and do this but I could survive with 8GB as I have good wifi and can tether my phone as well.
The PSV original imo isn't very comfy and I can't play it for too long of periods so I would recommend trying the new model and old model(and with cases if possible) to find the one that's most comfy for you
Edit: Oops haha, had this written out last night but just sent now XD







