If you are going to need substantial equity infusion(s) start and stay a "C" corp.
If you are based in New York City and choose LLC (assuming pass-through tax status, the main reason for using an LLC) all investors will receive K-1s and likely will have to file New York State and City returns and pay taxes on the allocated income, whether or not you have done cash distributions to cover the obligation. For smaller investors the cost of the tax return alone can be a disincentive.
There are operational and financial reasons to avoid unnecessary conversions from LLC to corporation. While the conversion is relatively simple from a legal and tax perspective you will have a new EIN/TIN which means you need to reopen or restart bank accounts, insurance policies, credit histories, ratings based accounts like unemployment or workman's comp, etc. You will also have to change "LLC" on all your webpages, printed materials, business cards, etc. to "Inc."
One of the most important reasons for being careful about conversion is that when you become profitable, you will have no tax loss carry forwards to shelter your first taxable income which means you will probably need to find additional capital to the extent you have to pay taxes sooner. For example, if you lose $2 million prior to profitability and pass the losses to the LLC owners, when you convert you will have foregone $2 million in offsets to taxable profits. At a combined 40% tax rate (and in NYC it might be higher) that's $800,000 in taxes the company will pay rather than retaining for working capital or investment in future growth.
LLCs are great for companies that will not need may equity infusions and are expected to generate lots of free cash flow but they are best used in situations where the structure can be relatively stable.