Blester - we have the same problems. Our company is also made up of many entities, including distribution centers (HFOs) and we have a couple of companies that manufacture machine tools. If Haas is the manufacturer you are describing, the company I work for is the largest distributor for them in the world. We are even opening some HFO's in China. If Haas is correct, what is your territory?
The system I created uses a combination of Lotus Notes, Macola, and Access. All of the transaction records and inventory quanties reside in our Macola SQL database, I had to create some new tables to track these. There is no data stored in Access, I just use it as a front end for all of the processes we do outside of Macola, which is everything after billing. There is no duplicate efforts and most of the processes are automatic or can be done with just a few clicks. It even creates the upload file for the purchase orders, so we're ready to go with that if Haas ever gets it working.
As for commissions, ours are also very complicated, I created a Crystal report for them to use and then they are calculated manually.
You definately need to get license for Crystal so that you can create (or modify the Macola reports) reports. It's not expensive. Good luck and let know if you'd like more info on what we are doing to work around Macola with this system.