Best Aurabot and MF build pair?

Me and my friend wanna play an aurabot and mf build and was just wondering which builds to use for each

For the MF part I don't think you can do better than Windripper, take your pick of shadow or ranger ascendancies.

The aura bot probably matters less, I don't think there are enormous differences between Guardian/Witch/Scion but I don't follow that subset of builds so can't say for sure. For league start probably whatever can be put together on less of a budget, or the one that is going to help an ele bow character the most.

Good luck lasting more than a week with this play style. Sounds like it would be great, until you find out it's more fun and just as profitable to have two people playing solo.