this is one time where Bigger IS better

(my wife is rather impressed with my winch btw

)
anyway ... *cough* Ive got a 9000lb Warn on my 88 LWB she weighs in at a hefty 2400kg loaded up, sometime ive been stuck deep enough to have to use a snatch block to get me out, Id go for at least a 9000lb winch .. maybe even a 9500-10000lb one if the budget allows,
usual rule of thumb is pulling power 2.5 times the (fully loaded) weight of your truck
Just remember that the winch rated pulling power is ONLY on the very last wind of the wire (so my 9000lb winch with 35-38m of plasma rope is pob only pulling a tad over 5000lb fully cabled up. .. when your stuck chassis deep in lovely northland mud .. 5000lb dosnt help much
BTW From a winch review i read a while ago Runva winches output was slighty under their rated pull .. not a lot but something to think about when buying a lower rated winch ... HOWEVER I used to have a Runva winch on my old Fez and Boy could she pull, Noisy and slow but never let me down

Oh and my experience with Pajero's and winches .... Upgrade your alternator to at least a 95 Amp one and run at least one 850 AH battery or better yet 2 battery setup .. the Runva's are good winches but like any winch they have a horrendous amp draw (my Warn draws 480 Amps in a short pull!!! ) .. I have a 1000AH truck in mine battery and try and keep my winch pulls as short as possible