Pedersoli makes a nice '73 in .45 Colt, as well as a couple really nice Colt Lightnings in both carbine and rifle lengths. My bro has the carbine Ped. Colt Lightning. Really nice rifle to shoot.
I think he uses 5744 and Tin Star for powders in both for cowboy action loads.
For medium power loads, Unique is a good one, for sure.