capitalroofer, I personally don't like having a sales guy make a sale and then hand it off to a project manager. That's just me. My thoughts are that a Sales Person who doesn't have to handle all aspects of the job is more likely to make promises they can't keep or over set expectations in order to make the sale. Then let someone else clean up the mess. I'd prefer they clean up their own mess which will teach them more quickly not to make those mistakes in the future.
Why would you commission the production side? I don't get that one. I view that as a salaried position.
A possible alternative though if you wish to do it that way. Consider each job having so much commission available total. Just for the sake of easy math, say that is 10%. If you want to break it down by sales and production, pay percentages for the different aspects of the job. For example, pay 4% for the sale, 1% each for inspection and adjuster meeting (for insurance jobs), 2% for shingle selection, picking up deposit, ordering materials, 1% for job day project management and 2% for finalizing and picking up the final check. Obviously, the breakdown is up to you. This is a good idea to do anyway in case someone leaves and has jobs on the book. You can pay them the piece of the pie they have completed if they don't stay around to finish the job.
You could take that same concept and use it with profit split. Let's say you do a 10/50/50 (10% of the job kept by company for overhead then a 50/50 split of the profits). So you would take the total profits after the job is complete and you cost it out then divvy it out on a ratio based upon your breakdown.
I hope that helps, good luck.