Dear Dom,
I trade futures (ES, 6E, CL) with NinjaTrader daily, and also been a professional C# developer since 2002 and create many of my own indicators and strategies for NinjaTrader. I'm a native-born American living in Southern California and speak good English. I have a BS and MS degree in Computer Science. I can provide a resume as well and also show you my trading journal and some of the indicators and strategies that I use to prove that I know and use Ninja.
I'm not the cheapest here but I think I'm the best match for someone like you for a longer-term relationship if you need someone to create lots of tools for you over time.
I have a question: What version of NinjaTrader are you using, 6.5 or 7.0 (beta)?
The reason I ask is because v6.5 does not support working with multiple time frames (range bars and minute bars in the same indicator). The only way to do this would be to implement it as a strategy instead, which does support multiple time frames.
If you are using NT7 beta then, yes, you can do this with an indicator as NT7 adds the ability to create indicators using multiple time frames, but it is still in beta.