I looked at the DUI units for the 300I6 but opted to go with a detached HEI system. I took about a day to figure it out, build the system and tune it. Works very well. But I had the run new ignition (start and run) wires from the switch the coil.
Price was the factor for me coupled with the challenge of DYI! I invested about $50.00 in the setup.

Glad it worked out for you. Woud like to see pictures!

Rod