Do you use IsBoxer? I think the easiest thing to do would use a VideoFX of your herber/miner's mini-map.

I made something where I could choose which toons mini-map to display. That might give you ideas.
http://www.dual-boxing.com/threads/5...map-select-box

I think the addon you wanted was Gatherer,
https://mods.curse.com/addons/wow/gatherer