Well from your intro, you want it for 4WD and as soon as you get it. You've also done your homework around the forum to know about the HG issues and probably the main other ones particularly the expensive ones relating to the VCU/IRD/Rear Diff - so do bare those in mind - don't get carried away at the thoughts of those green lanes - remember to use your head as well as heart
At 146K miles its not a spring chicken and with known issues with the transmission, you want to check it out as best you can. I think the only thing you can realistically do is the 1 wheel up test - it will give you an indication of whether the VCU is OK and that should imply that you've got the best chance of the other bits being in an OK state as well. It'll also tell you if the fluid has been drained from the VCU or bits taken out of the IRD - its its running 2WD. You can also get under and have a look - see if the rear diff mounts look OK, give the props a tug, see if the diff moves or the front/rear pinions. Remember at 146K miles it should be on its 3rd VCU by now.
VCU bearings are not an expensive job - but don't take what the sellers says is wrong as definitive - he may know its something bigger, or not really know what's wrong anyway. I think "bearings" is a sellers automatic response to any strange noises - it doesn't sound expensive to fix.
As for 146K miles on a K Series - not so sure about never having got there if the head had been done, you could just as easily say it couldn't get there without the head being done. There's a great Rover/Land Rover dealer near me that never sell on a K series without replacing the head gasket - doesn't matter how many miles its done, they always change the HG to an uprated spec. Personally I wouldn't buy a K Series, but if its managed 146K - it aint doing to bad is it!
Good luck, hope you get a good one!
