Well, based on your OP, I would say that the smartest approach at this moment is to 1)figure out where you are, 2)figure out what you have or can get, 3) figure out where you want to be in future, and then 4) figure out what you need to do with 2) in order to get from 1) to 3).
I realize that this is generic to the point of uselessness, but the trouble is that there is not enough information in the OP for me to get much more specific than that. I quite like the learning organization model, for example, but in order to bring it to bear on a nonprofit there has to be an organizational commitment to articulate concrete goals within the original mission; otherwise it all trails off into gasbag meetings and feelgood sessions and shortly thereafter the doors close.
Here is what I mean: the immediate problem – which seems as though it is an inability to make decisions as an organization or possibly a failure of consensus on the decisions which are being or have been made – could be coming from a number of places, from a weakness in the mission statement to unclear delegation of power to simple weariness on the part of the volunteers. Where the problem is coming from dictates to some extent the nature of the solution.
There are many other ways to go – many nonprofits operate from a board dominated structure, such that each board member is responsible for a single area (fundraising, program, budget and finance, and nominating usually) or as they get bigger there are board comittees for same; under these is a CEO, and answering to the CEO are people who manage development/finance/operations/planning & marketing/pr & community events/volunteers.
Membership organizations have a diffferent kind of model, which is more fluid and allows for changes to the bylaws as the membership votes for them. In any case, governance, program, and central administration have to be served for the organization to sustain itself. And of course if you have nonprofit tax status, somebody needs to keep an eye on the bylaws and foundation documents to be sure that they reflect the reality of the organization.
I find myself unable to make any kind of concrete suggestion as the original problem is articulated. You have identified one solution, which seems to be a proposal to formalize the decision making process or to delegate power more explicitly. And that may be the right solution, but there isn’t really any way to know what structure would best serve your organizational mission without knowing what factors are presently at play, where the difficulties have arisen, and what the goal is.