Case Study - How Should I build my Investment Pitch

I have an interview with a Growth Equity team and am building an investment pitch to be grilled on during the interview. How should I go about constructing the investment memo? Is there a standardized way of doing this, or certain things I must include? Should it be one page or expand to multiple? All bullets or some full sentences/paragraphs?

Also, they gave me a few portfolio companies of theirs to choose from. The company I like the most is one that the interviewer has worked on directly. Should I choose one he hasn't that isn't necessarily as good a company, but they know less about?

Additionally, what other questions should I expect? Any particular technicals to brush up on? Any follow-up questions on my memo to expect?