There are faction alternatives for Sponge such as “Niebek / Eagle Factions”
Just so your aware, Bukkit plugins can not interact with modded items properly unless the emulation of Materials list has been completely changed. In the case of Thermos, it doesnt modify the Materials list at all so you wont be able to interact with forge mods from Bukkit plugins.
Also
there are emulation attempts for Bukkit plugins to run on Sponge. While none are currently active, based upon you using Thermos im guessing you dont care about that.
PoreRT: GitHub - Maxqia/PoreRT: [Abandoned] Run Bukkit plugins on Sponge natively! (Batteries now included)
Original Pore: **Discontinued** Pore - A Bukkit-Sponge Bridge