I think people are missing which forum this is posted in... "Forex Brokers"
The futures recommendations might not help him.
If it wasn't for the NinjaTrader requirement, I'd suggest looking into Oanda or Pepperstone
Edit: I also recommend Dukascopy, but they too don't connect with NJ.
If from the US, and need to go with a US broker for NFA/CFTC regulations, then Oanda for sure.
But since the OP wants to trade through NinjaTrader (and I don't blame them, great platform) then you'd be limited to the forex brokers listed as partners of NJ... Maybe PFG Best or IB (and IB isn't as costly as you might think all in.)