If fuel is an issue you will be able to run that on veg oil which is cheaper to buy but returns less mpg. Its the same engine as in my Delica and baring a chuffed up turbo (which could have happened to any turbod motor) its been pretty reliable for the last 5 years.
Yes its slow to get up to speed but once there they run very nicely. The ride on my Delica is fine so I cannot imagine how the Pajero could be worse. They do lean in the corners but they are tall so you just drive accordingly. The Pajero should come with more toys that a UK spec Shogun as the Japanese love optional extras.
Mine was a Godsend last winter, I work rurally but live in town and it didnt miss a beat getting through the snow to work.
Insurancewise it wont be a killer, I pay around £350 a year fully comp in Blackpool parked on the street, which isnt bad as my Mrs pays about the same for a Scienic.
Parts are a piece of cake as a lot of bits for that will be standard shogun and any additional stuff you can get through places like Milners 4×4.
Space wise internally the SWB is crap in comparison to the LWB and doubly crap compared to mine which seats 7 properly with bags or 4 with full family camping kit.
I would recomend going on POCUK for the low down if you dont know what to look for when viewing.