しとけ ＝ しておけ ＝ する + おく
Combined with に, this する means "to choose", not "to do".
「どこにも行くなここにしとけ。」 suggests that someone has been looking for a good/best place for something, and the speaker says that no more searching is necessary because that place has been found, which is "this" place.
So, your translation is already good. ここにしとけ literally means "Choose this place for good."
This ～～にする is extremely useful at an eatery:
Tokyo Nagoya: 「みんななんにする？」 = "What y'all having?"
Girl A: 「アタシはコーヒー。」 = "A coffee for me."
Girl B: 「わたしはアイスティーにするわ」。 = "I'll have an iced tea."
Girl C: 「なんにしようかな～。やっぱコーヒーにしとくわ。」 = "What should I have? I guess I'll have a coffee."