We are a small group of developers and we want to create a Future-like MMO which will combine City building, RTS, Economic and Political type of games.
We are unsure if we should develop a DirectX9 engine from scratch or use tools like XNA, DXstudio.(we have experience creating a simple FPS-like engine using DirectX)
Another question is if engines like UnrealEngine/ UDK, Unity are really an option for a complex game like ours(most games developed with these engines are FP/3rdP Shooters)?
Any idea for where to start with the engine will be helpful.