Do yourself a favor, if you are a US citizen and doing business in the US, get a little legal advice and decide on an LLC or S Corp. I use LLC's for most everything but I also don't generally raise money from institutional investors so that's fine. But at least with the LLC I have more protections and a separation between private and business assets and accounts. Lots of details I am just glossing over, but you get the picture. Setting up an LLC (or corp for that matter) is not expensive, do it in your home state don't mess with Delaware and then foreign registration within your state etc. Of course, if you are looking to raise institutional funds then my advice would be different.