First thing to decide is what is end goal use for the truck and your budget. Is it a daily driver with light duty or will it be used to haul/tow heavy loads. Unless you are a good fabricator with the skills needed putting a "new" frame under the truck is not as easy as it sounds and takes time. Buying a chassis aftermarket gets pricey. I believe it is far easier to keep existing frame and add driveline parts to fit your needs. Good luck
