Yes this me, Paul Bryant builder of Exhaust systems.
And yes I do make a full system, see this page
Viking Exhaust | Facebook for all that I build.
I can set the header up to suit what ever Silencer/Muffler you would like to use, or build one to your style/requirements.
With this complete 3 into 1 system as shown on my bike below (Red '06) K&N Filters and a tune to suit we are getting around the 160RWHP mark, approximately 33% over stock.
I think Dains muffler looks O.K. when it is mounted, I can't comment on the performance and sound as I don't know.
This photo shows my Header with a reducer to step down to the Stock Headers 1¾" tail pipe.
This allows this to plug straight into the Stock CAT (all models) or into any aftermarket rear end system that you may already have. D&D slip on's for example.
My header into a Rinehart Muffler.
My header into the Stock Roadster CAT and Silencers.
Cheers, Paul.