There are several good gold detectors out there, GB2 is one of them. The Minelab Gold Monster is another good, but better one IMO. The Minelab Equinox is another one that is both good for Coin, Gold and Relic. Do your homework and watch a LOT of youtube videos so you can understand what each can do. Bill has got some great videos out there on both the Monster and the Equinox as well as how to hunt for gold.
IF YOU ARE NEW TO DETECTING, be patient and be persistent because there can be a big learning curve in both coin/relic AND in gold hunting. So don't get discouraged if you don't find a gold nugget your first few times out. With some folks it took some time and multiple trips to the field before they found their first nugget so there is a lot to learn in gold hunting. First thing first when you settle on a detector, get to know it, how to use it and how it responds to different targets. Recovering targets and developing your style falls in place next. Your adventure begins there.....Good Hunting!!