If its an auto you're after then you only have the choice of TD4 and V6.
The V6 consumes an awful lot of fuel, but if you're only doing low mileage it may be an option. I've never driven one, but they're supposed to be very nice. If they go wrong though, they can often be a right bugger to fix. To be honest, I'm not sure if you wouldn't be better off getting a V8 D2 because they don't burn that much more fuel.
The TD4 is a is pretty reliable, on a run will do 40mpg, but an auto around town will drop into the high-to-mid 20's. Its a BMW engine, but don't believe the hype that that makes it any better! It is pretty good, but suffers problems related to the common rail fuel injection - which I suppose all common rail engines would suffer from (and that's any this century!). The fuel lift pump and regulators and sensors relating to fuel pressure do give problems, but are fairly easy/cheap to resolve.
For your budget you should get a great car. F1s are great value for money. They are reliable and when things go wrong there's lots of suppliers and parts are cheap. They're also easy cars to work on if you intend fiddling yourself. I say this also coming from many years running Discoveries, the Freelander is so much easier to work. I've had my (Rover L Series diesel) Freelander for 9 years now and its been boringly reliable!
The important thing when buying Freelanders is the transmission - not the gearbox, but everything past that. It is not like a Disco with a center diff. The prop shaft to the rear axle is a direct drive (like having the Disco in diff lock). If the prop went straight to the rear diff, that would obviously be a very big No-No - but the Freelander has a Viscous Coupling splitting the prop into 2 pieces which allows 'so much' slip - enough for turning and slight discrepencies in tyres. It will though 'lock up' at higher rates of slip - eg when the front wheel lose grip - this automatically enables the 4WD (AWD really) capability. This works really well (I say that having driven Discos) but causes problems if not maintained as the VCU can get to tight or tyres can push the VCU into essentially locking up and all the problems that entails. So regular checks on the VCU and tyres should be performed and all 4 tyres should be the exact same make and model. Have a read of this...
https://www.landyzone.co.uk/land-rover/tests-new-freelander-1-owners-should-do-on-their-car.312863/
Obviously the points raised there are important when buying/choosing your Freelander. As people don't know much about them, you should always budget that it will need a new VCU (and you might as well throw in its support bearings) - so about £300. You should make sure it has exactly the same tyres on all 4 corners, if 2 have been replaced, they need to go on the rear. That's not just a budgeting issue for tyres, if they are wrong, its a worry for the transmission's integrity. Have a look under the car - there should be prop shafts, as well as the exhaust, going front to back - if there's not, its running 2WD. Similarly, its a good idea to jack up (just) a rear wheel and see if it turns fairly easily - it should only turn a couple of inches, if it turns freely, the drive to the props has been removed and its once again running 2WD. If you can, and its difficult, change the oil in the IRD (front diff), if it comes out with a metallic sheen, that's the bearings worn down and it'll need a recon.
This makes it sound like a right dogs dinner buying a Freelander - a lemon you might say! However, check the tyres, check it has props, check the props are connected (jacking wheel) and take it for a drive. Make sure you take tight turns, make sure you reverse on full lock and make sure there are no clunks, bangs or untoward activity. Some slight drag ('braking effect') can be expected reversing on full lock, but it should be hardly noticeable. An alternative is to get a really good condition one with low mileage but horrendous rattles and bangs for under £1K - put a new VCU, recon IRD (about £700), tyres and probably a few other bits and pieces and its good as new (proviso the rear diff hasn't gone to).
I should add that running a Freelander 2WD isn't the end of the world - it depends what you want out of it. Mine's 2WD, I miss the 4WD, but its a great reliable, cheap to run family wagon. You may have issues with insurance and MOT though.