I have two cavity holes in my front teeth, roughly how much would it cost to crown them? And what is the best natural crown type

Cavities. Without knowing the exact extent of the decay, it is hard to determine what treatment you need and what the total cost would be. Simple fillings are less expensive that root canals, posts, and crowns. That being said, since fees vary so widely from town to town and office to office, a fee quoted you over the internet is meaningless. Seek the advice of a local dentist who is going to treat you.
Options??? There are several options for repairing your front teeth, depending upon the severity of the decay, remaining tooth structure and if the nerves of the teeth (pulp,) are affected. Need an exam and x-rays to help determine the treatment and cost.
Ask your dentist. crowns can run around $1000.00.
Ask your Dentist. Without examination/imaging there is no way to advise you. Your teeth may not need crowns, but instead may benefit from a different type of restoration. The type of restoration or crown that would best serve your needs will be discussed with you after your Dentist has all of the requisite diagnostic information. Please seek comprehensive Dental examination and then listen carefully to choices.