What is the best brand of metal detector ?

Hi is any body can suggest me what kind of metal detector I have to buy , have around 300 pound looking for best metal detector it must be good for gold ,silver, platinum. Was thinking about Garrett ace euro it will cost me about 290 pound, just not sure how deep it can go , for e.g. , large amount jewellery in 1.5m -2meters deep just please give me some advise about all metal detectors as I never had one thanks.