If you choose the SP01 remember that the roster model does not have a decocker (I am forced to know these things too). Unless I'm mistaken you will have to manually decock it at Make Ready in Production. I believe this is the "preferred" SP01 model (because trigger jobs are easier and maybe better), but manual decocking is beyond my comfort level. YMMV.
Just getting started too, and thinking about all the same questions. Good luck. FWIW I chose a 9mm 1911 because I like heavy and thin, and I want to be able to afford to shoot it lots at my low level (so not .45). Couldn't find anything I liked for Production on the roster.