If you loved Necromunda, my understanding is that you will love Shadow War, as it is basically Necromunda reprinted. You could, with some work, easily field "gangs" from Necromunda there. In addition, while the focus is on Codex forces, I think there is a lot of variation and alternate lists to choose from, with new ones being added officially by GW in White Dwarf etc.
I think someone flexible and imaginative like you (and with a supportive group) could have great fun with it.