Let's see we currently have:
Leather
Goatskin
Boarhide
Peistskin

There can also be:
Raptorskin
Dodore Leather
Ureus Skin
Coeurl Hide
Gryphonskin

Premade alliances are in the works with the Alliance Party UI coming in 2.2. Probably some of those new maps will be there too and Either Raptorskin or Gryphonskin will need a 24 man party.