Depends on how similar. There are most certainly ways to manufacture around patents. You`ll have to look at the claims of the 2 existing patents to know for sure. You can do that at www.uspto.gov
That is also where you would start your patent search to make sure you are no infringing on someone else`s. Just because you don`t see your product on the market doesn`t mean someone doesn`t hold the patent to it. Only 3-5% of all patents make it to market.