This is going to be a personal preference. A safe seat is one that is mounted correctly with belts that are also mounted correctly. It's also one that fits correctly. Some people don't like seat back braces, which are required on non FIA seats. The least expensive FIA seat is the Momo Start for around $350. I've had a Kirkey aluminum seat before, now a Momo Start. A seat with a head restraint is going to be safer than one without. My next seat, hopefully this year will be the Racetech 4009 HR.