I think you may be looking for the two barrel Weber.Perhaps the Weber 32/36.I found my setup on Ebay.If you look in Weber VW you may find most of what you need to get started.
You will want the manifold and intake runners off the VW pancake bus engine.The intake runners will have to be angle cut fairly precisely and re-welded so as to get a good fit onto the heads.Im not positive if the flanges that bolt to the head are similar in size so its possible you need to fab new ones.(this im not sure of having a pre-made setup).
One thing I would change on mine would be to have better heat transfer to the entire setup.The Warmup is rather slow.Condensation forms on the manifold and intake runners.
Im currently fabbing something to rectify this.If it works I will share it with the two goldwing forums that I belong to.
Having access to a machine shop at work has been a blessing.
Even with that the prototype is still in its infancy and may not be the be all end all solution.My feeling is it has to look like it belongs there and definitly has to benefit the setup.
Carb Innovations made some setups but they are out of business.You still may find them somewhere somehow if your look hard and have some patience.
The best of luck and I applaud you for wanting something different.Im 95% happy with my setup.The unhappy part is cautiouslybeing addressed.