IMO, you've made the right first step by deciding that the carry gun needs to be a .45. Best advice I can give
is to find a range, if possible, that can rent you several widely varying styles. I tried 1911's, double-stack guns,
other single-stack guns, DAO triggers, single-action triggers... You need to find what conceals well, fits your
hand well, and allows for a natural trigger movement that you can develop good habits with. As you are no
doubt aware, any single gun recommendation might turn out to be a gem or a turd in your hands. I settled on
a Sig P220 Compact Carry in a Milt Sparks VMII IWB holster. I wear a suit everyday; your normal will likely come
into play on some of these decisions as well.
Try as many as possible before buying, is what I'm trying to say. Good luck, and thanks for carrying.