Metal Detector Mods

What is the best metal detector for the job?
I am currently searching the net for a metal detector … I've never used one before and the new the fans. I'd like a decent detector with all the amenities you are looking for precious metals, but at the same time can be easy to use. as I am an adult I do not want a cheap tacky, or an amateur. I have a budget of £ 300 – £ 600, so anything around that price would be nice. Everyone out there know what I should go? and I should know about brands and even better models?
I own 3 of gold nuggets that I have 2 machines a great trac Treasury wolf, Goldmaster VSAT and whites, for hunting relics, coins and general home sites using a Fisher cz7a, all machines are super, I've had for 7 to 8 years but are still well and good machines, which are always adding little things to them to be a little different looking but are still basically the same, gold machines use a lower frequency and the seeds are small, I'm talking about the size of a pinhead, the regular operation mill machines will not. Could you describe the art of metal detecting for hours and not have enough space. But the price of 4 to 6 hundred should get a good machine. Oh, I will mention you want to look medeorites have to use a gold machine.
day 2 of field testing Minelab 3500 metal detector mods