I found that this couple it's convenient for me.

In Toodledo you can set the contexts, the notes, the tasks and the lists. You have also some other options but you can choose which field you use and you can feel at home.

I use also at work Toodledo, I open a second window and I have my list in front of me at the desktop.

In the main time Toodledo sync with Ultimate, and I have all my tasks on my pocket device always with me to capture, to view, to use.

When I use Outlook for the email then I can forward my emails to Toodledo, so I put into my system. For example I can send to toodledo as CCN and then I have my emails as @waiting for.

The cost is 5$ for ultimate and less than 20$ per year for toodledo, but I think the benefits you can have more than that value. Toodledo has also a free account with less characteristics.

In both their web sites, you can see also some comparing tables between these apps and you can see which fit as the best for you