Your Mechanic is right about all what he said to you. If you decide to go with low dust pads, I gurantee you they will fade in no time and won't stop the car just as good. Not to mention the squeal that will evolve as a result of fading. You will end up replacing them soon and resurface your disks. Stay away from Kleen wheels. Let me explain why? The distant between the disk and the wheel is very crucial for brake heat dissipation and that is why wheels are torqued. So, imagine putting Kleen wheels in the middle. You are basically blocking heating from escaping. This heat is WHAT WILL WORP YOUR WHEELS. Big $$$$$$$ to replace. I suggest to live with the dust. Just clean them once a week. It is much safer when you stop the car. I only buy PAGID brake pads. They are by far the best. The same applies to ATE, however, I believe they are one short step behind.
PS. Rememeber that the people who designed and tested the car know better.
1993 190E 2.6
Advanced Diesel Systems Test and Research Engineer