Ninja 650 saddlebags w/ passenger?

I'm looking to do weekend touring with my girlfriend on an '07 ninja 650.

We're arguing over to how best to carry our gear. enough for picnics and more than just a spare t-shirt each.

Tank bags, saddlebags (panniers)?

do i need specialty kawasaki ninja bags?

i think she won't be able to sit on the back with saddle bags there (legs won't fit over)

she thinks a tank bag won't be enough space and will get in the way of my instruments.

thoughts? anything is helpful.

fyi i'm a big guy and she's more of a petite girl. everything on the bike is stock and i'm not looking to spend a lot of money. any bags i add should be easily removed.

thanks!