There's no reason why you can't establish this organization as a business.
Looking at INCOME:
Your members would still get the benefits they've signed up to receive.
They could still pay a subscriber fee to be part of the organization.
(Look at the financial model of Magazines. Subscriptions are like dues.
Think of Playboy - publication and members.)
They could still pay for attending the annual gathering.
You could still receive advertising revenues, from members,
from businesses, from the website (if any).
What you can't receive are deductible donations - since it won't
be a non-profit organization. But, let's face it, it's often easier
to get sponsors or advertisers than donations.
If you were to establish the business format as an LLC or S Corporation,
any profits, after all expenses are paid, would pass through to the personal
tax returns of the shareholders (S corp) or members (LLC).
You couldn't take a salary if it's an LLC, if you own part of it.
But you could if it's a C or S corp.
In an LLC, as a managing member, if you own a piece of the business,
you could get a guaranteed payment. That's kind of like a salary,
except you have to pay all the self-employment taxes personally.
In an S-Corp or C Corporation, you may have wages.
In a C Corporation, the company may even pay for your benefits,
like medical etc. It can't in the S corporation if you own 2%
or more of the company.
If I were to run this as a business, instead of an association, I'd set
it up as a C corporation. That way, nothing flows through to any person's
tax return. I'd establish the Board of Directors or an Advisory
Board that could vote on policy, programs, staff, budgets, wages, benefits etc.
I would make sure that all the money was spent (or allocated to a program)
before the end of the year, so there was no taxable profit.
You could get wages. You could get benefits - medical coverage,
retirement plan, etc. The Board members could get an honorarium
from the income.
You could hire staff as the organization grows.
Whatever you do, since it involves so many people, do take this to
a good tax professional who can evaluate the goals all of you
want to achieve. Don't save a few bucks trying to sort this out
yourselves. You don't want to find yourselves bickering about this
later and pointing the finger because someone didn't dot an "i" or
cross a "t".
If you tell me where you're located, I may be able to recommend someone
who can help you.