First of all, you need to know your budget.
You should have substancial income to keep an suv. Both are very reliable vehicles, except a few that are not taken care of properly.
Lexus Cygnus, comes with a 4.7 litre v8 engine. It consumes 10 litre engine oil and gives an average of 4 to 5 km, max 6 on motorway and it has a fuel tank of 93 litres. Driving it 1000 km a month in a city will cost approximately 20 k so as going to Lahore from Isb and coming back. On a 5 k fill up from the petrol station you will get 255km. Tires will cost you around 87 k, all 4.
Land cruiser 4.2 litre diesel from Japan are basically the vx limited and the ones imported from Uk are called Amazons. The 4200 cc engine consumes 7 litre engine oil, and 1999 to 2003 models fuel average is 7 to 9 km. 2004 to 2006, 8 km to max 11km on motorway, you can get 9.6 km in city aswell. Parts are easily available. Just use a good quality engine oil, i used to get fuel filtres from UK. I would suggest you not to use guard filters. A quality filter is a bit expensive but plays its role well.
Both of the suvs drives well, Allahamdulilah have kept both, but if you compare it, using the diesel varient is much a wiser option. I dont know whats your occupation, the diesel varient will not stress you at all.
If you need any help or info, you can PM me.
Regards.