Try BBTask Pro (about $19) - it allows you to set multiple sort parameters (category, date, priority) and has a number of filtering options. It can run a little slow if you have a very large number of action items, or so I've heard. I use it with about 50 - 70 items/projects without noticing any significant lag in response time. I think it's very solid, and I've had no issues relating to Notes integration.
The reason I chose this over Next Action is the ability to sort by date field. I'm not certain if this limitation still exists with Next Action, which I think is otherwise a good option (and more consistent with GTD's date-less next action list, if you're a purist).