  Supergravity backgrounds dual to a class of exactly marginal deformations of
N supersymmetric Yang-Mills can be constructed through an SL(2,R) sequence of
T-dualities and coordinate shifts. We apply this transformation to multicenter
solutions and derive supergravity backgrounds describing the Coulomb branch of
N=1 theories at strong 't Hooft coupling as marginal deformations of N=4
Yang-Mills. For concreteness we concentrate to cases with an SO(4)xSO(2)
symmetry preserved by continuous distributions of D3-branes on a disc and on a
three-dimensional spherical shell. We compute the expectation value of the
Wilson loop operator and confirm the Coulombic behaviour of the heavy
quark-antiquark potential in the conformal case. When the vev is turned on we
find situations where a complete screening of the potential arises, as well as
a confining regime where a linear or a logarithmic potential prevails depending
on the ratio of the quark-antiquark separation to the typical vev scale. The
spectra of massless excitations on these backgrounds are analyzed by turning
the associated differential equations into Schrodinger problems. We find
explicit solutions taking into account the entire tower of states related to
the reduction of type-IIB supergravity to five dimensions, and hence we go
beyond the s-wave approximation that has been considered before for the
undeformed case. Arbitrary values of the deformation parameter give rise to the
Heun differential equation and the related Inozemtsev integrable system, via a
non-standard trigonometric limit as we explicitly demonstrate.
