RF Microcontroller Selection
You could take a look at NXP's JN5148. Comes as a surface mount module containing micro, loads of I/O and RF, stacks for various flavours of RF comms including ZigBee and uses Eclipse as the development environment (supported under Windows). I've used it at work and eventually intend doing a load of automation stuff at home (i.e. when there's this mystical thing known as "spare time"). 

There are dev notes showing how to power them from a coin cell for low power intermittent use, and Farnell stock them.