He should be able to get in to an Isuzu Trooper/Bighorn/Monterey 3.1td for that money, and although I'm biased of course I'd say that's probably your best 'beater' 4x4. Mine's coming up to 200,000Km with no service history, and bar needing the auto locking hubs to be re-greased and a lower balljoint to replace it's doing great. The 3.1 engine has a rep for being very hard wearing, the later 3.0 was definitely a step back in reliability.
If he's looking at the Toyota's I'd say steer clear of the 2.4 Hilux. I was looking at getting a 2.4 Surf a while back, but my commercial vehicle mechanic friend swerved me away from them as they have a tendency to crack cylinder heads and he told me he wouldn't help when it all ended in tears

The larger engines are ok though apparently, in the older Hilux Surfs I believe you could get a 3 litre petrol V6 which would be nice.
I'm heading out shortly, but down the road from me is the place I picked up my Isuzu and he's had several for sale since so I'll poke my head in and see if he's got any. The bloke I used or moving my cars mentioned he was due a couple back when he delivered my Legacy so I'll drop him a text too.