I searched for Prado 91-95 about three years back and came to know that:
1. 90-93 models came with 2LTE 2446 cc engine with square shaped dashboard. Price range 8-11. This engine has got in built fault of head crack. You will see that most of the owners of this model change this engine to 1KZTE 2978 cc, which has got enough torque but it is fuel thirsty. But in my opinion only the engine change is not enough unless you change its gearbox and differentials as well.
2. 94-95 models came with 1KZTE 2978 cc engine with round shaped dashboard and new interior. Price range for a trouble free vehicle could be around 13-15 lacs. A very well maintained 1KZTE can give mileage upto 10km/l on long routes and 7-8km/l in city driving.
3. The problem while searching for jeeps is that you will find mostly tempered vehicles either body change or book of some other auctioned vehicle etc. try to avoid auctioned vehicles as most of them are tempered or atleast abused.
Three door prado are well known for over turning damaging pillars, the reason is its width to height ratio, if you want a 3 door prado I would suggest you to go for 1996 model onwards RX or RZ, its simply pocket rocket very handy in city drive as well with good fuel economy as compared to 5 door versions and it can accomodate family of 3-4 persons and luggage. New shape and good styling if I have to go for a 3 door thats the only model I will consider.
4D56 is not meant for highway drive actually these 2400-2500 cc toyota and mitsu engines hardly meet the requirements of these non aerodynamic design jeeps, thats why prone to head cracks the suitable engines are atleast 3.0 ltrs. Secondly 4D56 wont take you more than 90-100 km/h on motorway with too much sound.
Three door versions looks nice and its really a very well performer in offroading but when you consider its practicality for trips to northern areas it fails due to the reason that it has same engine like five door models with far less space.
About the comfort see this thread we did it and enjoyed alot without any problem
And the most amazing thing is that at every fuel pump station my 60 has got the least fuel to fill up although there was a SWB pajero having 4D56.
So finally I got an HJ60, 3980 cc, 6 cylinder diesel engine, 415000 kms driven throughout in private use, mostly in original paint, the factors which I considered before buying it was that its an old school vehicle with no sensors and very less hassles, its like a pure mechanical machine, so considering its age she wont let you down anywhere up north by some malfunctioning of its sensors etc.
Parts are readily available from montgomery road lahore and are cheap, did all preventive maintainence from Toyota Ravi motors, put new Yokohama Geolandar AT/S and enjoying the ride.
Its giving superb fuel efficiency of 8.5-9 km/l with AC in city and 10 km/l on highway at a speed of 100 km/h, although I was quite frightened by its 3980 cc in the beginning but then read alot of forums on www.ih8mud.com regarding it usage, reliability and running cost.
The most enjoyable thing is that I slept in it by folding its rear seats on my recent camping trip to Rohtas fort, by folding its rear seats you get a 5'-6" x 4'-9" (bed enough for two persons) just lay your sleeping bag and you can sleep anywhere in it provided the weather is good. Its not possible in a three door.
Its really rough and tough machine offcourse its has not too much accessories but its like a camper vehicle, you can have plenty of luggage in it.
Whatever the vehicle you go for keep atleast 200 thousand margin for new tyres and its routine maintainence incl. all oil & filter changes etc. I just came back from 2700 km journey from skardu, deosai and hunza in just 6 days from Lahore, and our journey continued upto 42 hrs continuous travel with AC with only one hour break each for breakfast, lunch and dinner etc., I really feel proud of my ride that she didn't gave any problem, really trustworthy but you need to have something without alteration and have complete preventive maintenance for such along and hectic journey.