Our previous article [Phys. Rev. Lett. 104, 060401 (2010)] predicted that Casimir forces induced by the material-dispersion properties of certain dielectrics can give rise to stable configurations of objects. This phenomenon was illustrated via a dicluster configuration of nontouching objects consisting of two spheres immersed in a fluid and suspended against gravity above a plate. Here, we examine these predictions from the perspective of a practical experiment and consider the influence of non-additive, three-body, and finite-temperature effects on the stability of the two spheres. We conclude that the presence of Brownian motion reduces the set of thermodynamically stable silicon/teflon diclusters to those consisting of layered micro-spheres, such as the hollow-core (spherical shells) considered here.