fixed implant solution

Think I may be looking at getting a full arch (top) fixed bridge but confused by all the different options i.e. overdentures, acrylic, titanium, zirconium etc. The timelines for healing where some say use temporary dentures and others suggest a fixed temporary on the implants. Number of implants, 6 - 8 , all on 4 ????. Need for bone grafts, sinus lift and read somewhere about placing implants at angles around the sinus are so no need for sinus lift. All very confusing. Is there anywhere/site that explains all of these things and the benefits and disadvantages.