Tranquil, Urn, Mek, Bottle, Drum
Dont forget ward and courier

book is a best, with skill 1 and micro he can do anything

tranquil..soulring..meka...pipe..drum..urn

and ur build depends on how the game is going..

lollero

usually hp and mana regen items like urn, mekasm, arcane and if u get really rich then get a heart or hex

There's no 'best' items for wisp. Just depends on the situation.

It mostly depends on situation.
If wisp supported good, he wouldnt have a lot of money(was buying wards, courier, etc, etc).
My standart build is bottle, magic wand, mekans, arcane/tranquil boots(depends if team is tanky or not), probably heart of tarrasque OR shivas guard in the late game. (just as the previous one)

I think it's impossible for Wisp to get full slots in one game.