Arm Microcontroller Programming

Hello, I'm needing to program an Arm microcontroller (STM32F4) to interface with motion control ICs via rs485 and to a Gainspan GS1500m wifi module. This will serve as a "wifi bridge" between the motion control ICs and an ipad app i'm developing. For development we are using the STM32F4discovery board by ST and a daughterboard we've made that has the rest of the circuitry required (the rs485 interface chip and the GS1500m module). I'd like to program with an easy to use (and relatively affordable) IDE like Crossworks for Arm, to program the chips in C / C++. Crossworks already has many libraries that are useful and they have a good reputation for tech support. But i'm open to other tool chains as well. Let me know what you think of this project and if it might be a good fit for you. If interested, message me so I can tell you more in depth information. If it goes well we would like to add many additional features in the future as additional projects. Thank you