I'm 6'1" and my detector still has a few notches in the shaft to let out, so I would guess you'll be able to swing without stooping, depending on the model you buy.
No matter what, detecting seems to be uncomfortable at first, until your body gets used to it and you figure out different ways to do it that feel more comfortable to you.
Nowadays the machines are a lot lighter, but still swinging one all day can wear on your arm a bit until the muscles get used to it. I switch arms when one gets tired.
Welcome to the hobby, I hope you enjoy it as much as we all do, and you couldn't have found a better group to bounce questions off of, so fire away!