[Gdeaver]

I think your going overboard on the sonars. You can't have all the sonars ping at the same time. Which interface do you intend to use, serial, pulse timing or analog? If you are going to use the serial , are you aware that the signal is at TTL levels but inverted? Sharp does have a new IR sensor that has 5 IR LEDs spaced at 5 degree. You mount the sensor on a servo, step through reading the 5 beams, move the servo, take another 5 readings. You could do the same with the sonars. You could use 4 and measure each 90 degree quadrant. Be aware that out side foliage and organic stuff doesn't give the hard ping reflections that indoor walls and furniture does. IR is also affected the same way but not as much. As for the controller the VEX for 150$ isn't really to bad. It's all packaged and enclosed. Don't forget the programming kit and easy-c upgrade. I have used Kronos robotics stuff. If you look at the web site there is example code for everything you want to do and there are several functions in the language for the sensors, servo control, etc. You may be interested in the Aires board. There is also an app note on using a PS/2 wireless controller. It uses a Pic 18 like the FRC. I kind of like the basic language. Way better than the stamp.