The Land Rover Discovey 3 and 4 and Range Rovers are both mono and ladder chassis, you can't get much stronger or safer and like Audi Q7 and others similar, these are the safest and best handling 4WDs on the road today.
BUT
Apart from the Disco 3 or 4, these are not particually good in serious off road conditions.
If you want good off road, strong and saftey on road, my pick would be in no particular order.
Land Rover Discovery 4 monocoque and ladder chassis IFS/IRS Airbag suspension
Land Cruiser 200 series ladder chassis IFS coils
Mitsubishi Pajero monocoque IFS/IRS coils
Land Cruiser Prado ladder chassis IFS coils
Nissan Patrol ladder chassis live axles coils
There are a couple I haven't mentioned, mainly because they have leaf springs.
Baz.
Not forgetting the Jeep Cherokee (2001 onwards) which has a monocoque construction with IFS and a live rear axle, and is a very competent off-roader and a good tow vehicle (especially the CRD version)
