Competitive VG Tutor and Gizoid
Athena said:there are no dual-typed Fire/Poison or Fire/Steel Pokémon
Heatran is Fire/Steel, though I'm not sure it counts as this seems to be a play-through team and Heatran is transfer-only.
As far as actually countering fairies (at least in-game) I've found it's better to simply use a pokemon that's not weak to fairy, rather than try to outright resist and just hit with powerful physical attacks of the same type as your pokemon,as long as Fairy doesn't resist said type. Fairy only hits three types Supereffectively and there are only a hand full of damage causing Fairy moves (further more, there's only one notable physical fairy move, so SpDef and HP are technically all you need to focus on to wall most of them). For example, you could use Flare Blitz Arcanine to not only resist fairies, but also hit their generally lower physical defense hard with a solid STAB move [STAB = Same Type Attack Boost].
Something like Togekiss (if you get ahold of a togepi, say through WT/etc.) could work too, since it has relatively high defenses and can shut down opposing fairies who generally cant hit it too hard by paralyzing with Thunder wave (lowering the foe's speed too) followed by flinching them consistently (60% flinch chance with Serene Grace) with Air Slash (60% flinch chance with Serene Grace. Fire Blast/Flamethrower make for nice coverage against steel types who would otherwise take minimal damage from Air Slash. Togekiss' Special attack is high enough it can deal with most steels easily through one of those fire moves)