Bento Beginner- Box Confusion!

Hello! I'm new to the board and also very new to Bentos. It looks like a great idea and a lot of fun! I'm always on the hunt for fun, different, healthy lunches so this just seems perfect. Anyway, I've been searching the internet for the past few days just looking at supplies, trying to figure out what I should get for starters. But when it comes to boxes, I'm overwhelmed! There are so many sizes, styles, brands, I just don't know where to start or what I would need. One of my main concerns is that the box be made out of a safe plastic. I read some of the reviews of plastics on the Just Bento article, but how do I tell what a particular box is made of? Stainless steel looks like a good option, but they just aren't as cute and many of the styles I have seen look like they would be a little bulky to carry around. Also, what about the safety of the accessories? I saw some cute rice shapers, chopsticks, all kinds of stuff that might be fun for later on, but I just want to be sure of the safety of the product before buying. Also, I'm really not sure what size I would need, how many layers, etc. What is a good size box for a lunch? I like the design (and price) of this model- Would that size be okay? And what about the safety of the materials? I'm so sorry for all of the questions, but any help would be greatly appreciated. Thanks so much in advance, I look forward to learning a lot from this forum!