Player Managed Reagent Hunting, GM Suggestions? Options

[Swing Kid]

The rules for looking for reagents are pretty straight forward, but if you have a mage in your group who is very interested in using their downtime looking for reagents, it would become pretty impractical for the player and the GM to manage this without taking up too much table time. Lets assume that the GM/Player trust has been earned (matter of fact, both commonly GM for the same group). Does anyone have any good house rules (or better - if there are references to books that may have been missed) for managing this, so the player can just manage this themselves?

For clarity, we aren't talking about rules for the actual search once a mage picks a spot, but rather house rules for getting an idea of how many times a person could look in a day (assuming they are serious about searching), how do they find the hotspots in the first place, etc. How to figure in potential confrontations while hunting, etc.