Are you looking at this one?
http://reno.craigslist.org/cto/3308016780.html
It looks clean from the pictures but can't tell... It does have a lot of miles.
Forget towing anything but a small utility trailer or a pop-up tent trailer. The brakes barely work well enough for the SUV itself, and the engine and AT combination just doesn't have the grunt to pull itself up the hills much less anything else. I don't know if it's the torque converter stall speed, the gear ratios or the power-band, but I can tell you that the Discovery 1 doesn't go up hills very well at highway speeds. And there's not much you can do about it. You can put D90 brakes on it but you're pretty much stuck with the transmission as is. You can change ring and pinions but with stock size tires it won't make much difference. If you go oversize then you'll have to change them just to make up. The motors can be tuned up but it's very expensive to get anything meaningful. Still, with nearly 200k, you'd probably get a worn cam and lifters to start with.
Fact is I registered just now to get some advice on what I can do about mine pulling it's ass up a little better.
Ha ha... not surprising your mechanic recommends a Land Rover.