Votes for Froslass and Girafarig. Typically chooses Abomasnow for Snow Warning. Sees little team benefit for that. Will miss its Electric and Ground resistances. Brings a lot of weaknesses, however. Hurts in a game with good coverage on strong trainers. Cannot easily work around them with its speed.
Liked using Froslass as support before. Combines good speed with your choice of Charm, Reflect, Light Screen, Thunder Wave, and Will-o-Wisp. (May be a bit difficult to get some before postgame, though.) Could allow Girafarig to set up Agility, Calm Mind, and/or Nasty Plot (with an optional Baton Pass). Learns a wide range of moves via TM too.
Current Virtual Pokemon Pet: Wigglytuff
Level 100 at 1468 posts
Personally, I'd go with the first pair - Abomasnow is a unique option with its grass/ice typing and I think Chimecho in addition to that would make for a fun, unique mix of party members. Though I'm definitely not denying Devalue's opinions on Froslass being a valuable coverage mon with a unique type combination + less weaknesses either.