Nitin Sacheti says some of the best plays on the A.I. boom are in lesser-known names. He's bullish on data center builders like Western Digital (WDC) and Seagate (STX). He’s also eyeing fiber optic companies like Cogent (CCOI), and is bearish on legacy software, satellite companies, and advertising. He shares his approach to finding off-the-beaten-path names with strong growth potential and reasonable valuations.