Your link looks like generally adequate advice. Here in the U.S., the machine of choice is by White. White's Metal Detectors have been in business for a long time. I don't know if they're available in the U.K. and I'm sure other manufacturer's have good machines. There are about three features you'd want on a machine that won't dissapont the giftee. First is AGB... Automatic Ground Balance, which is circuitry that will enable the detector to balance out the mineral content of the earth giving better penetration. Secondly, VDI Visual Discrimation Indication... this is a series of numbers that are displayed on the screen that assist in discrimating against the bane of all enthusiats, that being the cast off pop-top rings from cans. Lastly, Beach Mode sometimes called water's edge circuitry which greatly enhances beach searching. My White's, which I've had for years, will cost about $550 to $1250 U.S., but again there are adequate beginner models for much less. Go to cheap and it will be a dissapointment and sit in the back of the closet instead of being used. (Be sure to advise the receiver, if unshcooled in metal detecting, to research the laws using such devices. They're all over the place here in the U.S. and one has to be on their toes not to offend). Best of luck!