Welcome to the forum. I am also new so you'll please excuse me if I take you wrong, but you don't sound poly. If your main interest is sexual variety and frequency, that's more the swinging mindset IMO. Poly is about finding other loves to complement and complete our family and generally stems from an emotional desire, not a sexual one. To be blunt with you, if my husband approached me saying he wanted more sex and a variety of women to have sex with (and it wasn't about love), I'd be insulted, offended, and it could probably be a relationship ender. And he'd feel the same if I came to him in that way.
Have you spoken to your wife about wanting a more active sex life with HER? Maybe with communication and honesty your sexual needs can be met without going outside the marriage.