I put the new Harley Premium Ride Double Cartridge Fork Kit and a pair of Bitubo rear shocks (from Traxxion Dynamics) on my '12 SEUC. After riding 1,000 miles on the stock suspension and coming from an '04 SEEG that had Traxxion AK-20 cartridges and Bitubos, I couldn't wait to get away from the crappy factory stuff. At "only" $400 (plus installation), the Harley cartridges are a very, very close second to the AK-20s in feel and performance, similar to what folks say about the Progressive Monotubes. I and my BSR absolutely love the ride from the Bitubo rear shocks, and at $750 for the pair (talk to Dan about being a member here), they're actually pretty reasonably priced for a fully-adjustable shock compared to Ohlins, Penske and a few others. Traxxion also sells Ohlins and I'm pretty sure they have an application for the Harley baggers.
Like you say, you'll never turn it into a Ducati, but you can transform the bike into something better than you ever thought possible with the right components.
Good luck and let us know what you go with.