Diane, you are absolutely right that acknowledgements shouldn't be restricted to WikiTree members. With that modification to my original answer, I would suggest that you could include those information sources in either or both, but I would do it differently for those two places.
For the "See also" additional sources, just the citation, of course with the link if it can be accessed online.
For the "Acknowledgements", the person's name, with a statement about why his/her work was so helpful, and (if it's not cited in the "see also" section) identification of the source he/she authored and the link to it, if available.