I don't like to really recommend any certain brokerage or software, because it seems each individual likes certain things and each person needs to look around and just pick a few that offer what they need and try them out. You know it ain't like their ain't HUNDRDS to choose from! LOL!

But I will say, I have never had any problems with any of the many brokerages I have used over the years. So I say pick a few of the lowest commission ones that offer what you want and need. I now use. TradeStation, OptionsXpress, TOS and MB.

Also the same on software. Look around and pick what you want and need. I use TradeStation and StockFinder the most, and also have AmiBroker.
But the TOS stuff seems to be good and something I may look into when time allows.
I just wish I was a programmer or a few years younger. If I was younger I would learn programming as soon as possible. Lots of stuff I do for myself and others, is programmed by others that know programming. I can only do basic stuff, mainly in TradeStation.
I believe StockFinder uses VB.net?

You mentioned NinjaTrader? I have also looked at that.
It is a very good software package and FREE!
It seems one can do about anything they would want to do with it, if they can program?
You also mentioned writing C#? Are you a programmer?
How about programming with the TOS software?
If you are a programmer, and know trading, you can be well ahead of the game.

Anywat try many and pick what you like, want and need!