Regarding of your trading style you want to trade with an ECN broker. ECN brokers get the liquidity and spreads straight from banks and hence have tighter spreads and better fills. Though they charge commission but you are better off paying commission rather than higher spreads.
Market Makers are usually notorious for manipulating prices in their favor and some also take opposite positions when you trade. Plus the spreads are higher.
In my opinion MBT, Dukascopy and FXCM Active Trader are good brokers. I use all three of them and had no problem.
Regarding MT4, you can use MT4 demo for charting and use any broker to place trades. Unless you want to run an EA then you need a broker with MT4.
Though don't just chose any MT4 demo...read my post
Are You Using Right Charts For Forex Trading?