Outdoor Robot project

I am designing an outdoor semi-autonomous robot. It will based on a simple two hubmotor(brushless hall sensor) platform and a caster. I have the LIFE battery for 48V and a Roboteq dual channel motor controller. I need advice as to what processor to obtain and programming help.

Development Stage 1:

Initially I would like to have the following:

Remote activated on and full stop. Initialization at desired heading
Remote activated turn of 180 degrees…and then follow that heading until the next turn button press. At which time it will turn 180 degrees in the opposite direction and maintain the new heading.
Remotely controlled overall speed and/or some random speed variation within a remote parameter.

I guess I need to know what sensor would be the most appropriate to obtain for heading information (compass, gyro, or both) and what brands are easily integrated into the VEX hardware/RobotC programming language,

Development stage 2:

I would like to add long range (maxbotix??) ultrasonic sensors perhaps in an array or moving scan and/ or LIDAR(Hoyuko UTM) to add reactive interaction between the bot and moving objects. As such I would like to know if these additional sensors are something that can be used by the VEX series of CPUs.

Short of going to labview/Rio which is overwhelming in price and understanding I am having a difficult time finding software/hardware which interfaces directly with these items.

Thank you for the help.