Netbase Duo Headrest DVD systems?

I've a long long drive this coming summer to France. To try and ease the pain of my two monkeys I've been looking at headrest DVD systems for the kids.

I could go the whole hog and have them upholstered into the headrest, but we're talking serious money, and I'm not convinced it's worth it. The other options being the headrests that can be bought with the DVD screens built in and have adjustable posts, but I'm concerned about the quality of these?

The other options are the ones that strap onto the rear of the seats/headrests or the ones (and looking favourite) VW are selling as an accessory, the nextbase system at £280. These ones 'bolt on' to the down polls under the headrest and then the dvd system clips on and off.

Has anyone got one of these systems and perhaps offer any advice or thoughts to consider before I buy.

Thanks

Bren