Advice on Dual Screen & Surround Cameras

Hi everyone just wanted to pick people's brains ESP those who already have the car!

I have ordered a Dynamic with a few extras which is coming out at the £39,500 mark which is more or less my max I could afford. I was really interested in adding the dual screen as I have a 6 year old boy & 1 year old girl who would both me made up if they could watch a movie on the screen in the car. This extra is £600ish but the problem I have is if I spec this I also have to spec the surround cameras £600ish otherwise I loose the reversing camera! Strange but true!!!!!

I do not want to loose the reversing camera so if I go for it it's gonna cost me £1200 extra. My question is how do people find the Dual Screen? Do you use it or is it just a gimmick? Same as the surround cameras I would not really be interested in these but with my situation it may have to spec it so are the cameras useful? Or again just a gimmicky toy? Would they both be worth the £1200 outlay or should I just keep my money in my pocket?

Buy a tablet or portable dvd for your kids. They (and you as well) will be more comfortable if they're in the back, they could share it, it will read more files, it will cost less, etc.
For the surround camera: the rear-view camera and auto-dipping mirrors already give you extra eyes where you need them most. Surround view is only really useful off-road imo.
I think both options are really nice, but I haven't specced them, even though I have an otherwise pretty loaded car (considering the EU specs).

I think I would go for portable dvd players for the kids in the back and save some money!