10 foot deep? Sheesk my man, what are you looking for??

Unless your item is a volkswagon, no metal detector goes that deep.
A toaster sized item you might do 4 or 5 ft. deep with a 2-box unit, but 10 foot deep? What makes you think someone buried something that deep? If you've ever dug a hole 10 foot deep by hand (like if you were in the army, and had to dig fox-holes in bootcamp), you know that simply to go 5 ft. deep is a friggin major chore!
Me thinks you've been reading too much oak-island superstition stuff

There is a popular misconception out there, that treasures are all super deep, for some reason. But on the contrary, bread and butter caches (jars of coins, or whatever) are found all the time just hidden behind walls, or a foot deep in the dirt floors of old cellars, or post-hole depth in the barn floor, or whatever.
And no, no machine is going to have a screen "tell you what it is". If you've been led astray by the whites commercial ("tells you whats in the ground before you dig") trust us: The commercial is b*ll cr*p (sorry to be so blunt, but so many people take it litterally, that's its gotten beyond comical). All the machine can tell you is conductivity. And unfortunately, a hub cab (which will sound quite nice to a metal detector) and a tool box filled with gold coins, are going to sound exactly the same. No machine can tell you the difference. And unfortunately, a lot of metals have the same conductivity, given their relative size (ie.: a gold ring and a pulltab for instance). And the quantity/size plays into it. So for example: a pulltab, and an entire aluminum can, have an entirely different conductive TID, even though both are made of the exact same metal: aluminum.
Perhaps you need to borrow a few different types, pork around at schools, sandboxes, yards, etc... to learn some basics. Then move up to 2-box units, graphs, whistles and bells, cache hunting, etc....