looking to get a new detector for shallow fresh water hunting.would the 800 with the two higher 20 and 40 frequiences be better? is the 600 just as good to get small gold rings,white gold, and small gold chains? is there an advantage to the 800 on these items?i really don't want to spend an extra $300 if i don't have to. i currently am using a tesoro stingray 11 which does well on these but is getting old, plus i could use an equinox better on land.