What is the longest range spectre?

I'm guessing it's Infernal Sentinel with Feeding Frenzy Support Gem on, or is it something else?

Here's a video of Infernal Sential support gem.

https://www.youtube.com/watch?v=BvcY0qLNMfY

I'm trying for a necro build that can snipe down enemies from a screen away so that the build is safer, even if it's a bit slower than something like solar guards or the more conventional metas.

Any thoughts?

frost sentinel most likely