Hi, first I will answer your 2nd question. Where to look? The exact tool to help you is your Geneology Report.
To answer the qualities, look in your Geneology for PSA who are active daily. Those who contribute and earn VP's, those who are striving hard to succeed in SFI.
Review also those who have been active but somehow stopped. Last those PSA whom you have referred personally but try to balance it out as you need those who are active.