Mine has the basic mini it's a much better size for small hands. Set parental controls (google for instructions). I would recommend educational apps for weekdays and game apps only available at weekends (start as you mean to go on). You can delete them up to the cloud and reload on a Friday.
Second the suggestions to get a mini. We got a refurbed one from Apple (comes with same guarantee as new one) - good option if you're looking to save a few £. Would also highly recommend this case. My DDs iPad has bounced many times and survived . Btw comes in different colours
My ds has a normal sized one with retina. He has a griffin cover on it which has protected it for nearly 18 months and with ds that is great.
We use loads of educational apps, yes he does play games but as a reward for using the educational ones.
He has just been awarded an ipad to use in school by the Inclusive technology support panel which was arranged by our SENCO. We had to supply evidence to support our application. Not sure if this is something that is available in your area, might be worth asking the question.