Warn winches (american) are pretty strong winches provided you get one with a decent capacity to suit your vehicles mass, but you will need a winch bar to house it. Dont do what someone I know did (who shall remain nameless ) and cut a slot and drill holes in a non-winch bar and then end up winching the bar off the front of the beastie! Most low mount winches either Warn or Thomas have similar mounts and bar manufacturers allow for either to fit.
I always found a hand winch far more versatile (you can pull backwards out of the sh*t you find yourself in or even sideways) cheaper too, but more messy.
If you go for an electric winch you might want to consider a second battery installation to keep the juice to it without flattening your main vehicle battery. (you can even jump start yourself... that almost sounds rude!)
Although I have been told its almost impossible to fit a second battery to a S2 V8..anyone done it before?