One key point here might be that SAAFE is not an organisation, it's just a
website full of articles and a forum for discussion.
There are organisations here in the UK (see the
Sex Work Projects forum section, and also the
Politics/Academics section), but they fulfil completely different goals to us. We just provide an online space where sex workers of all kinds can anonymously discuss the issues that affect them. We do not offer any "real life" support, though we do often recommend that certain posters get in touch with certain projects/outreach groups/healthcare providers if they have certain needs or requirements IRL.
Setting up a similar online space for US workers is a really good idea, but bear in mind that the moderation of any forum is a difficult task. You'll need to set strict rules and enforce them ruthlessly; people get so bonkers on the internet that an entire online community can be ripped to shreds with bickering and trolling and whatnot in a matter of hours. Sounds a bit dramatic, I know, but people are people and it doesn't matter whether it's a real life or internet-based group - keeping the peace is sometimes tricky but always vital.
Speaking as an individual sex worker, now: I don't attend any organised meetups with publicly advertised times/locations, because I am not "out" and so I would feel very vulnerable and afraid of being seen. I do try to meet other sex workers as much as I can but prefer it to be in much smaller numbers (like just a meetup of 2-3) and arranged privately so I can basically vet prospective friends in the same way I'd vet clients. I expect them to do the same with me! I really wouldn't be happy to trundle along to something in a publicised location where someone else had arranged everything. But that's me and definitely doesn't apply to everyone. I just thought I'd add that because it may be a concern if you want to set up an RL group - you'll probably have to focus on "out" sex workers, but that's fine.
I would probably start small with something like your idea, especially in the US. You don't want to attract too much attention as that could be risky. And, to speak very frankly here, many people who do sex work are slightly bonkers (same as any industry, really!); not people you would want to trust with sensitive information about yourself. But a network can start with one friendship and go from there. You don't need 100 members overnight!