Which ipad to buy

That is a very difficult question to answer without more information from you. The first thing I suggest is that you get an iPad. with as much physical storage as you can afford. You cannot add more storage to an iPad like you can with a computer. If they want to play the latest video games on the iPad, then a device with a faster processor would be a good choice. Of course, what you are willing to spend and and can afford is obviously important.

You can compare iPads here and see what you think.

https://www.apple.com/ipad/compare/