  We study higher-dimensional non-supersymmetric orbifold models where the
Higgs field is identified with some internal component of a gauge field. We
address two important and related issues that constitute severe obstacles
towards model building within this type of constructions: the possibilities of
achieving satisfactory Yukawa couplings and Higgs potentials. We consider
models where matter fermions are localized at the orbifold fixed-points and
couple to additional heavy fermions in the bulk. When integrated out, the
latter induce tree-level non-local Yukawa interactions and a quantum
contribution to the Higgs potential that we explicitly evaluate and analyse.
The general features of these highly constrained models are illustrated through
a minimal but potentially realistic five-dimensional example. Finally, we
discuss possible cures for the persisting difficulties in achieving acceptable
top and Higgs masses. In particular, we consider in some detail the effects
induced in these models by adding localized kinetic terms for gauge fields.
