I bought lock and fold seats from exmoor trim as I wanted to put my two young kids in the back in their car seats and these appear to be the only legal option.
The seats are heavy and expensive and I had some fun and games with trying to get them to fit - they need to be raised off the floor with a spacer otherwise the mechanism jams and you can't turn them round - as they are capable of facing sideways as well just not with the child seats fitted.
Also, you wouldn't want to be too tall because I'm only 5'6" and my head is brushing the headlining.
The kids, particularly my 2 year old son, love coming off-roading though. Having paid all that money for the seats allows me to go out with wife and two kids without being nagged that I'm going off roading on my own again... what price no nagging!