The first thing is knowing your budget & then you can research anything up to that limit. I'll back ERA because that is what I know. ERA makes a great car that you can get in anything from kit form to a turnkey car. A good start is to have the frame powdercoated & the body bonded. From there you can choose to assemble what you like or have them do it for you for a fee.
http://www.erareplicas.com/