On the plus side, our car is fairly heavily modified and still tows very well. The important thing for your trailer is that you keep the towing hitch at the right height, about 18 inches, and I'd imagine for the nag (horse?) that the ride isn't too harsh. If cash permits fit a Dixon Bates shocklink to your towbar. If it doesn't don't worry too much, if you have gas dampers already the ride won't get a lot harder.
If you lift the car you will probably use stiffer springs so I'd suggest avoiding that for now, as we often say it's damned expensive to lift a Disco properly and the springs are just the first step, budget on around £700 to do the job right!
The anti roll kit is probably anti roll bars and possibly stiffer bushes in the front radius arms. These bushes are distorted when the body rolls so stiffer ones resist it. Leave this alone for now, you won't like the car if you remove it.
Henry was right on the nail when he started that other thread, you'll see that most of us who have spent loads of cash advise the same first few things, then keep your money in your pocket until you know why you need to spend it.
The basics are:
Recovery points and recovery gear (ropes and shackles)
Protect what you've got, Diff guards, steering guard
Tyres
DON'T GO OUT ALONE!
If you stick with a group of mates you will always come home, see what gear they have and ask why etc etc
