You may try something like ChopleBerry-Tyranitar with Unnerve (to circumvent Chople Berries) to 2HKO Snorlax with Low Kick. It doesn't have STAB Fire but has an overall great movepool both physical and special. It's jsut that you have to delay Trick Room for a few turns because you won't get to OHKO.
Another one that comes in mind is Hariyama who can OHKO most Snorlaxes with Close Combat even before Guts activates. Besides it has a good elemental coverage and some nifty Wifi moves like Detect and Wide Guard. Both of them are faster than Snorlax and slow enogh to utilize Trick Room to some extent.
If you prefer a more defensive approach you may have a look at Sableye who can burn Snorlax with WoW even under Trick Room thanks to Prankster. It is pretty splashable because it has no weakness but it still has a hard time against Fire types (immune to WoW) so you may send it out with Jellicent who poses a reasonable threat to them.