Basically, your gun will follow the series 70 parts, but to select the exact parts you want, you have to know the basics of the 1911 engineering layout and the common alternate layouts. The is not super hard, but there are a few surprises. The Kuhnhausen manuals are a great reference, as is your gun builder. Also, your gun builder should know what parts make good combinations and what leaves you with a pile of crap. Frankly not all aftermarket parts are equal. I would not want a customer the exact part to use. It should be a 2way street. You shoul insist on thing you care about, but let the gunsmith persuade when quality and time to fit come into play.
For example, some beavertails are a quick fit. Some brands are a bad match to your SA's lines and will never fit right without welding.