VCs want to invest into a C-corp because it allows them to have a flexible share structure so if you're seeking VC money, C-corp will be a must. But, in the mean time, you CAN use S-corp since it is easy to set up and gives you some protections. S-corp can be easily converted into a C-corp (a single supplemental form!). LLC is not as easy to convert to a C-corp and paperwork is fairly complex and will cost you several K.

Thing to note about S-corps is that all founders _MUST_ be American citizens.