I recently got permission from an early 1900's property to dig their privy, and am going to be purchasing a probe. I also dig at dumps as well so I am wondering what length probe I should get and is there a good website I can buy one for? I see regular "soil probes" on the internet for sale ranging from $20 and up. What should I look for in one or should I have one made from an ex-digger? Thanks for any input!