There's a game from White Wolf called
Hunter: the Vigil that has about a score of hunter groups. The page at
http://en.wikipedia.org/wiki/Hunter:_The_Vigil lists most of them, and there are various fan pages out there that give details. Some of them just don't fit what you are looking for (for example, there's a government backed group and another that's the arm of a corporation) but others are closer to what you want - and you can pick elements from any of them.
The closest one to what you've mentioned is:
The Ashwood Abbey – Thrill seekers who want to experience everything involving the supernatural from the most benign to the most psychotic (torture, mutilation, and worse).
They are a group of rich, bored people who started off as a Victorian Hellfire club (drinking, drugs, and sex) then discovered the supernatural. They'll have sex with a werewolf, then hunt it down, then have a drunken orgy to celebrate.
Back in the DV, there are hints that the Church might be connected with a hunter group. Then there's the
Venatori Umbrorum. To quote:
The Venatori Umbrorum are literally “hunters of the shadows.” Often characterized as “Masons with machine guns” or “Masons with flamethrowers,” they are an ancient secret brotherhood of people with extensive knowledge of academic (especially history and folklore), commercial, intelligence and counter-intelligence, financial, legal, and military issues. They possess an understanding of basic occult countermeasures. They are a larger organization than the Fellowship of St. Giles (possibly even larger than the White Council realizes). Unfortunately, they seem to lack powerful magical practitioners.
As allies of the White Council, they usually provide intel and analysis to the wizards. Since the start of the Vampire War, they have also participated in combat operations against the Red Court.
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They are listed as allies as of the White Council, but that could be a marriage of convenience. The Venatori Umbrorum might be a bit anti-wizard as well, but working with the White Council to hurt the Red Court.
Hope this helps.
Richard