I have thought of going the CB performance way. However it would take up too much of my budget.
With regards to cams - there are many way to get around the uneven idle. Most people forget that on the stock unit there is a rather largeish chamber in the inlet manifolds. This is called the plenuum chamber. Its function is to even out pressure from the airflow.
On a stock 1.7 like mine the cam is not so hot hence you can get away with no plenuum chamber using the Inlet manifold as it has more than enough volume to handle pressure increases.
However on a Type 4 2.0 race engine I used to run I developed a kick ass FI system - it never got finished as the car itself (a chop top drag beetle) was sold on. The cam was a G-Grind on that engine hence I had to use plenuum chambers. It was set up on a twin inlet manifold with one litre plenumms sat on top of each with an output on the top leading to the central body of the FI.
The general rule is match the size of the engine to the size of the plenuums. That was the pressure variance is equal. You also need to connect the pleuums up to balance the pressure waves.
It sounds to me like our 911 friends are trying to run a hot cam on an engine which has low cam plenuum tolerances.
They would most likely get better performance out of their cars by increasing the plenuum size
I will let you all know how it goes
Chris G