If you really want to tweak the 5.25 - send it to Springer Precision. Have them do the competition trigger which is their kit + some additional trigger work. I'd also have them install the Dawson front sight with a larger fiber, texture the grip, and add the tungsten weight to the guide rod. The gun will still be legal with the tungsten weight as you're running the factory recoil spring guide rod.
Again, if you're looking at the 1911 platform, the easiest way to get into it would be to call CJ at 1911 Heaven
for a Les Baer. He stocks more Baers than anyone (about 1,000+ guns), and actually sells about 70% of what Les Baer makes. He may have competition models in stock.
I've purchased two guns from CJ and he's a pleasure to deal with.
Brazos Custom also stocks tweaked STI's and Bob can make additional modifications in a short amount of time.