Yup. That under bonnet shot is not of that truck. That's a 4.0 with LPG.
To be honest, I'd be looking for one of those. The fuel consumption of the 2.5 is not a great deal better than the 4.0, add to that a lack of power and a manual box with 4WD you can only use off road and there really isn't a lot of point. You get a much better auto box with proper 4WD attached to the back of the bigger lump.
XJs can be had for pocket money prices at the moment so I'd hold out for a 4.0L Just be careful to check for rust on pre 97 (face lift) models as the earlier ones were not galvanised and are prone to rot in the floor, sills, rear corners and roof.