The key here is to deploy a workable system in order to gain some deterence in a crisis situation. Whatever we build, the specifications will be classified in the hopes that the enemy won't gain knowlege of the system's limitations.
I am reminded of the Navy's development of the first Polaris missile submarine. They basically took a fast attack sub, cut it in half, and added the missile room to the center section. This cut years off the development of a new sub and allowed the Navy to deploy the Polaris System years ahead of schedule. That was an example of a successful "crash" program. I suggest that we take a similar approach now and get something deployed.