i've been down this road many times for myself, friends who couldn't weld and customers.
running one pipe off of the exhaust, then splitting to duals, is a waste of effort and the resulting sound is not worth it.
only a dual outlet split manifold, or headers, with true dual exhaust will give you that sweet six cylinder sound.
any welder worth his salt can build you a nice split exhaust manifold. george asche in pa does a great job at splitting a stock manifold, if you can't find anyone near you to do the job.
headers are also available through stovebolt engine co.
you can taylor the sound from loud to quiet by choosing the right mufflers.
using true dual exhausts, you will be very pleased with the sound and wonder why you didn't do it sooner!
