It is not possible to give you an opinion in this case because I do not have enough information and would have to see you and your X-rays. Yes implants do have to restored with crowns and other prosthetic appliances.
it is impossible for me to suggest a treatment plan for you without seeing you and examining your mouth, models of your teeth, and films, and discussing all the risks, benefits and alternatives of any plan you may wish to proceed with. You seem to have gotten 2 different treatment plans. such makes it tough for the patient, I know. If I were in your shoes, I'd see a prosthodontist (one who specializes in more involved cases) or a general dentist who has alot of prosthetic expeience and request a written treatment plan that includes fees, time frame, and exactly what is to be done and the order of such. Ask for alternatives--at least 2 of them. And ask a ton of questions. Much goes into your decision-- your age, the time frame for completion, cost.... Ultimately, the decision is yours...
What I can answer is that "implants" are titanium fixtures that are inserted into the bone. When they integrate, ie when the bone has firmly attahed to them--which takes time---they need to be "restored"--that is to say that prosthetic teeth (crowns) need to be placed on them. Look at it this way-- the implants are the roots and the cowns are the teeth. the fact that you are unclear about what exactly an implant is tells me that you have alot of learning to do about what may happen in your mouth. This is why 1) you need to find a friendly, caring and experienced dentist who will sit with you and answer all your questions and 2)you are not ready yet to do anything. You don't know enough.You only get one shot at this.....and unfortunately you are responsible ultimately for your own healthcare. hope this helps.