Squee more winter whites
My chubbles have 8 inch ones, Saph has a wodent wheel (unpotty trained lol) and Topaz has a Karlie as she goes to the loo in bed
Any larger for them would be too big, any smaller and they wouldn't fit.
Balls are debateable, i stopped using them a while back, as i have a large playpen now, but others' hamsters love their balls. Your choice.
I thought they were awful climbers at first but Topaz proved me wrong. Her tube is pretty steep, leading up to her second cage, and at first i was worried she wouldn't manage it but she's more than capable! She also loves climbing bars. But yeah, so long as they're not vertical they're fine.
Shavings are fine, my girs have megazorb and finacard mixed together but anything will do.