American Libertarian an antonym of Libertarian socialism.
I am aware of this. Although, we were the first to use the term in the political sense, and we kind of want it back. 
But the best part about a Anarcho-Capitalist Society is that you can go off and start a commune with like minded people in a sort of Socialist Utopia without the government breathing down your neck.
That was sort of my line of thinking. Or rather, without the assistance of the state, proprietary enterprise would have a tougher time muscling out cooperatives and worker-managed enterprise. People who desire freedom should naturally gravitate toward the latter institutions if they truly desire emancipation in all aspects of life.
So if you want to make the American Federal Government Socialist or force socialism on the rest of us who dont agree with you and use the threat of force to steal peoples money, then no. I dont think the FSP is for you. But if you want to practice Socialism with a willing group of people free of the government, then yes, FSP is for you. Though in my experience i have yet to find someone who is the latter...
I suppose that makes me the first then.
Is the FSP capitalist, or is that an oversimplification?
The scope of participation in the Free State Project is contained in the Statement of Intent:
I hereby state my solemn intent to move to the state of New Hampshire. Once there, I will exert the fullest practical effort toward the creation of a society in which the maximum role of civil government is the protection of life, liberty, and property.
The statement of intent does not explicitly state who can and cannot own capital property. But it personally strikes me as contradictory that a person could be forbidden from owning capital property or that such property might be confiscated by others for productive use.
It's the vast difference between the capitalist versus the libertarian socialist view of property rights that concerns me, and that seems to be what your personal concern revolves around.
as long as the "socialism" is voluntary, i for one am all for it!
I wouldn't have it any other way. (though I'm inclined to inquire as to why you chose to put socialism in quotes)
"Capitalism is what happens when governments leave things alone." --Ludwig von Mises
I disagree. Without the government, the last thing protecting capitalism is the ignorance of its victims.
If your intent is to start a voluntary commune, cooperative, or worker managed business, which people can choose to join or leave, then I absolutely support you in your effort, and think you would definitely fit in.
In fact, I think all of these are a cool ideas, and might consider joining one for a period of time at some point. It's coercion, and the threat of aggressive violence that I oppose.
I am somewhat concerned on this point: Do you disbelieve in property rights, and if so, would you consider it morally acceptable to take a person's legitimately acquired property -- by which I mean something they have produced themselves or acquired by willing, voluntary trade -- by force?
I strongly agree that the government works in favor of the big corporatists, and routinely muscles out alternative organizations. Burdensome regulations custom made to eliminate competition and raise barriers to entry are a favorite tool.