Thanks for your replies everyone.
First of all I want to emphasize a few things that I might have not been very clear about. First of all, this project is for a race car, which means that we are not intending to mass produce the board. Second, the reason why I cannot design the board from scratch is not so much because it is a student project but more because I am the only person working on the embedded system part and there are significant time constraints on when the system should be available for testing. Thus, I was not looking to purchase something that can be mass produced but rather a board that was almost ready to go into the car and would need a few minor tweaks. The bulk of the work is designing the algorythm to run the control system. There are plenty of general purpose boards available on the market that are intended for use in real applications and not as evaluation boards. However, I thought that there may be companies that manufacture microcontroller boards that can operate under heavy conditions. That turns out to not to be true so far.
It seems that right now the best solution would be to use a general purpose board, solder out the IO connectors and replace them as necessary and then put it in a shockproof (and other -proof) casing. I have seen some examples of production systems (like engine control units that come off the market sealed in a plastic case filled completely with epoxy so that only the outside connectors are accessible. The heat is not an issue since the control tasks will not be extremely complex and should not draw any excessive power.
I like the idea of servo board used to interface with the motors and as a matter of fact I have considered such an idea (robotics sites are definetely the best for that kind of stuff) however the exact type of motors is still unknown and will be determined after the necessary calculations and design are complete.
Thanks again to everyone who replied! Best regards
- Mike