[REQUEST] Help with Mega Salamence EV Spread

[CSquared1025]

So I'm still relatively new to Pokemon competitive play and therefore I always have trouble building strong teams so once again I'm starting fresh and building a new team that is centered around Mega Salamence so far I have the moveset and nature but can't think of the best possible EV Spread that will make him hit as hard as possible outspeed pokemon but still survive so at least one dragon dance can be used.

So far I have this:
Salamence @ Salamencite
Nature: Adamant
Moves:
- Dragon Dance
- Roost
- Double Edge
- Dragon Claw
EV Spread: ???

All I'm sure about is having full investment into attack.