Vamo V3 and Provari are both good mods. If you are concerned with the 510 only threading on the Provari, you can get an Ego adapter if you wish.
The chrome on the Vamo V3's is very nice. Super crisp and good reflective chrome, very attractive. The price tag is also pretty attractive compared to a Provari.
My honest recommendation would not be for either the Vamo V3, or the Provari though. I would go for the ZMax V3.