I am currently using Boss Capital (see Boss Capital Review). I’ll start by saying that no broker is perfect. Some provide fast withdrawals yet have trading platform issues, such as a distinct lag that often doesn’t get you into trades at the price you preferred. This, for example, explained my experience with Markets World.
Few of the brokers give you a choice over charting; most have web apps that combine the data feed with charts of their chosing.
Some of the traders do provide tools like MT4 or MT5. However if what you really want to do is investigate the market and try out different signal providers and strategies you really want to get the three parts of the system; data feed, analysis and execution in different places.
I still haven't found a way to get a raw data feed - the article on charts here on this site still describes charting in terms of data being supplied.
Any help? I'd write an article myself but I'm a techie. Better I collaborate.