Consensus seems to be that a decent 100 series Diesel with the 'AHC and IFS 'mods' is the long term way to go for most overland trips...can't really see myself getting into the sort of terrain that would demand a 105.
For the moment as I 'get up to speed' 'll stick with my 80 series petrol/LPG - I've only just started getting some work done on the car, and everything I spend I am hoping to 'transfer' to a 100 series if possible...
(John, (the other one) - I had my petrol 80 series converted to LPG about 6 months ago - the guy that did the work was recommended to me by Greg at Landcruisers Overland - cant remember all his details off hand, but he did a multipoint system for me, doughnut fuel tank etc for about 1500 GBP - have to say it has made a big difference - before the conversion was getting about 120 miles for 60 quid of unleaded

since the conversion I'm getting about double that on LPG (LPG about 80 p per liter at present but hoping the changes in Libya will see that drop back by 5p/7p before next summer

)
Minor mods to my 80 series so far: 4 x new BFGs, CB and a 3inch suspension lift (Front and rear slinky springs,front and rear Ridepro Rox extended travel shocks , lower bump stops and anti-roll bar brackets etc.), extended diff breathers. (will try and post a pic or two when I get it back)
Was hoping to take the car to Wales this weekend on Onelife Adventure break, but rear springs delayed and so car up on stands right now :-(
Will add snorkel, new custom sliders, front bumper/winch, rear dual swing out bumper in the spring, decent audio/sat nav and then try to get out and about on a few trips to see how I get on..
Certainly longer term I wouldn't bother doing anything else to the 80 series, petrol/LPG outside of Europe would be no fun, so will most likely advertise it towards back end of 2012, either with all the mods in place, or stripped back to standard setup if that makes sense (I have the original springs/shocks/wheels and tyres)
BTW I had an X plate (2000) VX 4.2 about 3 years ago - used it exclusively on road for work and pleasure -was a fantastic ride BUT then I ran into AHC issues, Toyota wanted almost 4K to fix it (car had done 60K miles!!), ended up using Ian Rubie and Julian V to effect a repair (replaced spheres etc) and then decided it was too much bother and sold it...(
bought a landrover 
and a 911 4S

) however reading this forum now, if I had known it's possible to strip the AHC out I may have decided that was a better option -
All the input much appreciated -
Tom Mc