Samson's team: Hariyama(Sheer Force), Mienshao(Regenerator), Lucario with Focus Sash, Hawlucha, Conkeldurr(Sheer Force)(Ace) and Blaziken(Speed Boost if I remember correctly).
Colour Wheel clown is still the best area to train up. It just takes a lot of time. Also, your team is generally underleveled, so i'd get them all to around 65 or so.
Mamoswine is less useful here, since he gets KO'd almost instantly. But if you can, use him to EQ the Lucario. It has a Focus Sash, so it'll live the first Eq, and if you outspeed you can hit him with another to KO him. Mamo with thick fat can also tank Blaziken if it uses a Fire move, and you can return with an EQ.
I'd suggest using Calm Mind on Gardevoir. Hypnosis+Dream Eater is just not good enough at this stage. Alakazam's Attack base stat is Atrocious so I wouldn't have Iron Tail or Psycho Cut.
Ampharos, just as a general suggestion, is a Special Attacker so Fire Punch is useless. I'd suggest Signal Beam, Discharge, Dragon Pulse and Power Gem as its moveset.