Sorry the HPN Vincent is refering to has been sold and also come with a sad story. The Michelin deserts fitted have a problem with speedwobbles on tarmac at high speed and the new owner came of the bike at around 140KM/H on a straight piece of tar.
The bike has some damage of witch the most serios is the frame.
Besides the problem we have with the tyres the bike have been absolutly great.
Handeling is greatly improved with the longer rake angle and wheelbase. The suspension is unreal and does not bottom even with heavy loads. Getting airbourne with this machine is no problem.
You should be able to do your HPN convertion for about the same price as a new 1200GS if your motor is in good order and you stick with your current brakes and electrics.
Sometimes it is not good to change to much on the bike as it is easier to get parts for the more standard items from your local dealer. Klaus at HPN will also advise you on this.
If you are interisted send me some mail as I have a prepared adventure frame and I can supply and advise you on anything you need from HPN. The biggest drawback at HPN is that there is quite a waiting list and it can take up to two years before they can finish a bike.