If you have less than 15 clients you will want to be an advisor at interactive brokers.
LLP's only if more than 15 clients, and any registration fees can be found at the secretary of state's business entity registration pages and will save you substantial amounts of money filing on your own. You do not need a lawyer to do this. Look up "LLP registration forms" on your secretary of state's home page. There should be a link to business filings, and I would not talk to a lawyer to do this. I started a general partnership with about a 1 page summary of what was being formed, who was involved, what the purpose of the agreement was, and how fees and compensation were handled. If you can get your clients to sign this, then there isn't any problem, as it will stand up in court, but just remember to get the signatures notarized.
Filing an RIA registration has taken nearly all year for me, and I'm still not done completing a disclosure document for my CTA.
These are only licenses you'll want to get, again, if there are more than 15 clients and you'll want to trade through IB.
Whatever you decide, I'd like to suggest becoming a model manager on Covestor, and getting your people to subscribe. They have plans to charge performance based fees to accredited investors, which, incidentally, is the only type of investor that you may charge percentages of profits from. It does not sound like any of your people qualify.
To qualify to be an accredited investor, you must have either 3 year spousal combined income of $300,000 or 2 years as an individual of income of $200,000 with expectations for that to continue. The other possible accredidation is $1 million of liquid assets not including primary residence. Only the above three allow you to charge percentages of profits, but can be overridden with all investors becoming party to your LLP or LLC.
These formalities aren't necessary and neither is speaking to a high priced attorney. You can take care of any of your filings through your secretary of state, and, as long as you don't sound like a complete moron and haven't forged anybody's signatures, having these documents notarized are really all you'd have to do to set this up.