In this paper, the outage probability of a noise-limited decode-and-forward wireless cooperative network cluster, subject to the Nakagami-m multipath fading and Gamma shadowing is investigated. The closed-form expression for outage probability, when the network fusion center selects the stronger received transmission out of the maximal ratio combined signal, arriving from the nodes acting as relays, and a repeated signal from the originating node, is derived. Moreover, special cases, in which the generalized fading and shadowing channel is reduced to several familiar propagation environments, are observed. The derived analytical expressions for outage probability are furthermore confirmed by running independent Monte-Carlo simulations. The effects of multipath fading severity and shadowing sharpness, average signal-to-noise ratio values, and network dimension on outage performance are discussed.