I have had the heavy weight machines and really loved the depth of them, but due to health reasons I had to go to a lighter machine. Thinking about getting a x-terra 705 but not sure what coil to get. I do a lot of coin/ jewelry hunting hunting in the parks and open schools around here. Once in a while I go to the pacific beach areas. From your experience what should I look for in getting started with a x-terra 705 ?