Please suggest a dosing pump

[Myka]

I'm going to start using a dual dosing instead of manually dosing my tank, however my tank is fairly low demand, and needs little dosing between waterchanges. So I need a doser that will dose quite slowly on a 40g tank, as I don't want the doser to act as an ATO. I'm going to buy a Tunze ATO sometime soon here. I'm trying to make my tank as self-sufficient as reasonably possible as I am working out of province as of late, and want to make my tank sitter's job as easy as possible. I would prefer a dual dosing pump to buying two single pumps.

Any suggestions on a slow dual doser that is med/high quality?