I thought long and hard about this in my old car, and eventually decided against it as I thought the temptation for distraction would be too great for me.
A 7" tablet with a small bezel (Galaxy Tab 3 7") etc will fit in most double DIN units. But you will likely need to mould you own fibreglass fitting.
If you wanted to connect with Bluetooth, your steering controls will probably work right away, but if you wanted to connect it via Aux you will likely need an adaptor. These do exist, but you will have varied results.
There are a lot of things to consider, but it has been done. And there are a lot of guides people have created (although not on Peugeot Forums) giving tips and tricks.
I found one. But it was in a foreign language. Lol. I have a tablet her. And the double din fascia. I have means to hold it in place. All I really need is all the wires, wireless charging dock, Bluetooth adaptor and can't think what else lol.