Apologies if this isn't the best place for this thread. For the last few years I have been studying, researching, and developing a trading system on TradingView for futures and equities. I am now at the point where I would like to begin actual trading, and need platform advice. I am considering either TradeStation or NinjaTrader, but I've also read up on MultiCharts, Sierra Chart, and Trading Technologies. Cost is not an issue. I realize that early on, it probably makes little difference which I choose, but I'd like to avoid having to switch platforms as I grow since I will need to port my custom indicators to whichever platform I choose, and that will take time.
I will be starting out small, but have the ability to scale up drastically over time, so I'm looking for the most reliable platform with the fastest executions, best fills, etc, that even very large traders are comfortable using. I also will try to automate my discretionary system at some point, so the most reliable automated platform with the best backtesting abilities is important to me as well.
Any advice is appreciated. I understand that other than TradeStation, the other platforms require a separate data feed/broker, so recommendations on that would be great as well (if TradeStation is not your recommendation).