Immersion blenders definitely have their place in processing, but they will not pulverize seeds and skins for a very smooth sauce. They work good for emulsifying ingredients, mixing in spices, and when clamped to the top of a steam kettle for keeping the sauce moving while cooking.
For creating a smooth mouth feel sauce, I have found using a food mill to remove the seeds and tough bits of skin or using the blendtec blender to get the best results.
There are commercial grade food sieves which would work in processes. You just have to figure out the steps, what has to be ground, what has to be sieved, how smooth does the end product have to be....
And how big of batches will you realistically be running, break down the different steps, figure out how each ingredient needs to be processed...
Just some thoughts....
SL