Deeds 1685-1709 Vol AA (which includes Wills) is available on FamilySearch.org. The complete Will with additional information on the payment terms to William is found on volume page 327 :
Notes on variants of the Ennes surname
For search results using Billard's Dutch Record Vital Statistics, check the exact match and whole words only boxes then use one of the variants: Ennes, Ennis, Ennist, Annis, Annist or Viervant, Veervand, Veervant, Vier-Vant, Vierbrand, Vuurvant.
Kingston Baptismal records for the children of William Ennes and Cornelia Viervant under variants include: Alexander, 1694; Cornelis, 1696; Catharina, 1701; Jennetje, 1703; Alexander, 1709; Wilem, 1712.
William Ennes, first husband of Cornelia Viervant, died between 1711/2 and 1715/6. The Marbletown(e) Tax Assessment List of 1716/7 include a Widdow Keettel £2 & Cornelia Ennis £10.
In 1717 the following marriage #367 is noted in the Kingston records: Lammert Brink, j.m., born in Hurley, and Cornelia Vierbrand, widow of Willem Ennes, born in Kingston. Banns registered, 21 April:
*"New York, Land Records, 1630-1975," images, FamilySearch ( https://familysearch.org/pal:/MM9.3.1/TH-1961-33165-7996-87?cc=2078654&wc=M9M4-NM6:n1110786057 ), Ulster > Deeds 1685-1709 vol AA > image 230 of 350.