To the best of my knowledge, it isn't possible to "pursue" CSAs (except by becoming a Team Leader and earning shares of Second Home CSAs).
If you're looking to build a team, then definitely PSAs are the way to go.
Use all methods at your disposal (advertising, S-Builder Co-Op, PSAs to Go, etc.) to get your PSAs and then teach them to do the same.
You're CSAs will be assigned to you automatically by SFI depending on your rank.
