Sup /vp/,

Looking for some help and advice to finish off this Noivern set I've been planning.

So far I have:-

Noivern
Nature: Timid
Ability: Frisk
Item: Choice Spec
EVs:x
- Switcheroo
- U-Turn
- Flamethrower
- Boomblast

It is intended to be a lead. Use Frisk to discover the opponents held item and either Switcheroo or hit and run.

I need help with setting the EVs up for this set and any advice would be much appreciated :)