Ultimately you are the only person who can truly give an answer to these questions, but I am happy to share my thoughts.
Annual Goal: How many new customer would like to win
From where I sit, this sounds like a bad idea. Now, I don't know if there is a sales manager, caught in too formalistic "thinking", breathing down your neck or whatever else may be going on at your place of work.
But, as far as I can tell, the pure number of clients ALONE doesn't say anything at all about the merits of their business they bring in.
You have to think deeper. What you want to achieve with your sales activities is a strategic advantage in your markets; but to discuss this goes outside of the scope of this forum.
In terms of GTD, yearly goals are often thought of as "Level 3 Goals and Objectives" maybe you want to research more on that. I personally don't do yearly goals, since I don't like to tie my goals to artificial deadlines.
Project: 2017 New potential customers. List of the companies I'd like to approach among which I work to achieve the goal.
In GTD parlance, this could as well be just Reference material. Maybe put a "Tickler" reminder to review this list from time to time.
But What I would do is to make every company on that list a project from the get-go, where success is defined as winning that specific company as a new client. It is thus much easier to organise this list. You can always put some companies on someday/maybe or add new ones. Just have every company one project and pronto. Keep it simple and flexible.
Project: Every new won customer (individual Folder in Toodledo).
As by my previous post, it depends on how you want to view your work. Typically in GTD a project is something that has a definite outcome, a point at which you can say that it is completed. What would be the end-point for these projects? And what happens, if you want to sell more to an existing client? And what happens if they themselves come back to you for more business? How do you organise that?
Taking a look at the cascade as a whole, I don't see a point in it. If you want to measure the success of your sales activities, take a metric bound in reality. I can't say anything further to it unless you share more details of your situation, but a real metric would be for example the profits you generate, or the percentage of profit share your combined clients have in their markets compared to what the clients of your direct competition are making or some such. You have to bound this to reality.
Surely it'd be also convenient make a Level 2 Area of Focus and Responsibility to schedule a daily time when I work on this goal.
As I wrote, it depends largely on how your sales process looks. For instance, if you make a lot of outbound phone calls or want to be available on the chat on your company's website, you will need to make yourself available during certain office hours. Again, if you share more details, one can share more specific thinking.
And I think the list of the new potential customers could allow me to be as fast is possible to set next actions where I think it's more important. Isn't it?
Sure. But as I wrote above, the same list as a subset of your Projects list would be just as fast.
Aside from that, you should set Next Actions all the time in a manner that makes your inventory of Next Actions complete, at any point in time, having set all possible Next Actions in their respective Context and at least one Next Action per Project (if that Project is not covered by a "calendared" or "tickled" item already.)
