
Because of its stable Attack and Sp. Atk., is better to choose Sp. Atk.
Rayquaza @ Wide Lens/Yache Berry
Ability: Air Lock
Nature: Modest (-Attack, +Sp. Atk.)
-Dragon Pulse (The best Dragon Special Attack, to deal with Dragons, STAB)
-Focus Blast (To break through some Rock and Ice types)
-Surf (If Rock is paired with Ground, this will be x4 effective)
-Flamethrower (If an Ice type is paired with Ghost, better use this)
*I selected Sp. Atk. better becayse Rayquaza got better Special moves. But if you select Physical as better, try this better:

Rayquaza @ Yache Berry/Lum Berry
Ability: Air Lock
Nature: Adamant (-Sp. Atk., +Attack)
-Outrage (To deal with Dragons, best Physical Dragon move, Lum Berry will do the rest)
-Brick Break (To deal with Rock and Ice type, also break walls)
-Stone Edge (To deal with some more Ice types)
-Earthquake (FEEL THE EARTHQUAKE, ROCK TYPES!)