We would like to use enough processing power to run our app, but not much more, in order to keep the heat down. However, we do like to have a math coprocessor. An Intel '486 might do the job, with an inexpensive and simple ROM DOS. We've used a Pentium for something similar, but many of the single board computer mfrs tend to ratchet up the performance (most people want this) and you get a lot more heat.
I agree it could take months, but we've used the "tool chain" before while doing the line-by-line coding method of software development. We were hoping that experience would help streamline the initial development of the "tool chain"
Steve G.