Problem with all these conversions is that at the end you still have to have the skill to pick the correct springs, rework the damping and generally set the suspension up.
Starting from scratch.
If you have the skills to do that the stock parts can be made to work just about as well as any exotica you can bolt on.
Just start with a good shock, I like Ohlins, but some well informed folk like Wilbers too.
Ohlins will usually have a fork spring / fork fluid recommendation to match their shock, leaving only the final dial in to be sorted out, and that is just trial and error.
And a little bit skill/experience.
FWIW the two worst set up bikes I have owned came with receipts from suspension specialists for replacement shocks, fork springs and set up so I dont recommend that course.
The best , my R100 GS with a second hand Ohlins shock and HPN inserts is near perfect at stock settings and is miles in front of any upside down fork / extended swinging arm bike I have ever come across, although I haven't compared it with any genuine HPN or Moorespeed bikes.
But at $ 1000- the modifications were considerably cheaper than either.
