I am not sure whether gucken and Dutch kieken/kijken are related.
Neither is my dictionary. ("Kieken" being also German, particularly far northern.) It does think that "kucken" for "gucken" is due to influence from "kieken".
'Kieken' isn't any dutch I'm familiar with. (though admittedly I'm hardly an expert on the 17th century or whatever.) 'Kijken' pretty much is the standard form. We also have 'schouwen', cognate with 'schauen', meaning 'to observe, to study closely'.
Interestingly (to those among you who like their Foucault, I suppose) 'schouwen' also a definite legal connotation.