P models shipped with buckhorn bars instead of drag bars. The risers were basically just taller versions of the upper sections of the drag bar pull back risers...
You can use ANY Harley, Honda, Kawasaki, Suzuki, Yamaha or aftermarket 1 inch handlebar. Both of my bikes happen to use Harley Davidson FL touring bars...

...that's Sam, the 2003 small cop bike. Stock base risers, 2" extension risers in the stock bases, FL touring bar with all stock controls.

... Pokey, the 98 vintage touring bike with FL touring bar in the stock P model riser assemblies.

... Pokey with the FL bars in a set of AEE style 6" rise aluminum dogbones. Knucklehead-Panhead-Vincent clutch/brake perch and lever sets. It does have a drum front end after all...
And just for the "Holy S***" factor... Pokey with the bars I liked best, 15 inch rise apehangers...

Make it yours. Have fun with it. You'll change it up several times during your ownership.