The ${\text{LiHo}}_{x}{\text{Y}}_{1\ensuremath{-}x}{\text{F}}_{4}$ Ising magnetic material subject to a magnetic field perpendicular to the ${\text{Ho}}^{3+}$ Ising direction has shown over the past 20 years to be a host of very interesting thermodynamic and magnetic phenomena. Unfortunately, the availability of other magnetic materials other than ${\text{LiHo}}_{x}{\text{Y}}_{1\ensuremath{-}x}{\text{F}}_{4}$ that may be described by a transverse-field Ising model remains very much limited. It is in this context that we use here a mean-field theory to investigate the suitability of the $\text{Ho}{(\text{OH})}_{3}$, $\text{Dy}{(\text{OH})}_{3}$, and $\text{Tb}{(\text{OH})}_{3}$ insulating hexagonal dipolar Ising-type ferromagnets for the study of the quantum phase transition induced by a magnetic field, ${B}_{x}$, applied perpendicular to the Ising spin direction. Experimentally, the zero-field critical (Curie) temperatures are known to be ${T}_{c}\ensuremath{\approx}2.54$, 3.48, and 3.72 K, for $\text{Ho}{(\text{OH})}_{3}$, $\text{Dy}{(\text{OH})}_{3}$, and $\text{Tb}{(\text{OH})}_{3}$, respectively. From our calculations we estimate the critical transverse field, ${B}_{x}^{c}$, to destroy ferromagnetic order at zero temperature to be ${B}_{x}^{c}=4.35$, 5.03, and 54.81 T for $\text{Ho}{(\text{OH})}_{3}$, $\text{Dy}{(\text{OH})}_{3}$, and $\text{Tb}{(\text{OH})}_{3}$, respectively. We find that $\text{Ho}{(\text{OH})}_{3}$, similarly to ${\text{LiHoF}}_{4}$, can be quantitatively described by an effective $S=1/2$ transverse-field Ising model. This is not the case for $\text{Dy}{(\text{OH})}_{3}$ due to the strong admixing between the ground doublet and first excited doublet induced by the dipolar interactions. Furthermore, we find that the paramagnetic (PM) to ferromagnetic (FM) transition in $\text{Dy}{(\text{OH})}_{3}$ becomes first order for strong ${B}_{x}$ and low temperatures. Hence, the PM to FM zero-temperature transition in $\text{Dy}{(\text{OH})}_{3}$ may be first order and not quantum critical. We investigate the effect of competing antiferromagnetic nearest-neighbor exchange and applied magnetic field, ${B}_{z}$, along the Ising spin direction $\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{z}$ on the first-order transition in $\text{Dy}{(\text{OH})}_{3}$. We conclude from these preliminary calculations that $\text{Ho}{(\text{OH})}_{3}$ and $\text{Dy}{(\text{OH})}_{3}$ and their ${\text{Y}}^{3+}$ diamagnetically diluted variants, ${\text{Ho}}_{x}{\text{Y}}_{1\ensuremath{-}x}{(\text{OH})}_{3}$ and ${\text{Dy}}_{x}{\text{Y}}_{1\ensuremath{-}x}{(\text{OH})}_{3}$, are potentially interesting systems to study transverse-field-induced quantum fluctuations effects in hard axis (Ising-type) magnetic materials.