If what you want is a relatively light all metal DA/SA handgun, there is little room for improvement as far as design or function are concerned.
Ergonomics may not suit you, and the DA to SA trigger may confound you. But for it's type it is about as refined as you're going to find.
Trigger kit... Not really needed, most find it is pretty damned good for a service pistol.
Tuning... Again, not really needed as they are boringly dependable from the factory.
Accuracy... Again, from the factory boringly so.
All you really need is a few mags and practice in transition from DA to SA.
Well except for a Titanium finish or perhaps Diamond Plate if pimping is in your future.