Now that Tesla CEO Elon Musk has hired advisers for his plan to take the U.S. electric car maker private, and the Tesla board has named a special committee of independent directors to evaluate it — two steps CNBC reported would happen last week— the next milestone is for Musk to actually put together a formal proposal.

(Ideally, this proposal would already exist, but let's table that point for now.)

Musk's offer is likely to include conditional financing from third parties, including Saudi Arabia's sovereign wealth fund, and may have requirements that a certain number of Tesla shareholders roll over their existing stakes into a private company, according to M&A bankers and lawyers who have worked on similar transactions. Putting these conditions in a proposal will allow Musk to show the board something quickly without having to secure tens of billions in committed financing.

It's also possible the Saudi sovereign wealth fund could commit much more in financing, but Tesla's cash-burning business, costly factories and Committee on Foreign Investment in the United States (CFIUS) issues make that less likely, the bankers and lawyers said.

Of course, Musk already tweeted he had secured financing last week, which has reportedly prompted an SEC inquiry. While conditional clauses may aid Musk's efforts in lining up financing, the SEC will only care about what he knew to be true at the time of his first tweet, said Thomas Gorman, a lawyer at Dorsey & Whitney and a former SEC enforcement attorney who specializes in financial fraud and market manipulation.

It's particularly important there is Saudi financing in the formal proposal because Musk has specifically said the country's sovereign wealth fund's interest in taking the company private was the basis for his "funding secured" comment," said Gorman.

"The SEC needs to determine if Musk's first tweet was a false statement when he put it out," said Gorman. "There must be some documentation around conversations about funding, even if it's limited. If the Saudi sovereign wealth fund has the ability and willingness to do this, and Musk knew at the time, you might not like the way he did this, but I don't think that's an enforcement case."

Musk did make reference to existing shareholders rolling their stakes into a private company through a special-purpose vehicle when he first tweeted about Tesla's take-private last week. The details around how such a fund would work weren't clear, and there's no obvious precedent for such a thing.

Musk said Monday he is being advised by Silver Lake on taking the company private. Silver Lake helped Michael Dell with his management-led buyout of Dell in 2013. It's likely Musk wants to emulate how Dell took his company private, Gorman said. Still, Dell dealt with a variety of obstacles, including counterbidders and deducing a fair price for shareholders, when he attempted the leveraged buyout. Musk probably won't have an easy time moving forward with a buyout even if he avoids the SEC's glare, Gorman said.

"He can't make the company do this," Gorman said. "If the company decides it doesn't want to do this, then it won't."