After hearing of some of the install issues, i'd rate TOGs above ZZP, definatly above S&S.
My TOGs has 0 install issues. It bolted in and sealed the first time. I didn't have to dick with starter wires, PS lines, nothing at all. I did have to figure out how to redo the trans dipstick, otherwise it was the best header install i've ever experianced on any vehicle. TOGs FTW and many who own them will agree.
Back on topic, if I were you and assuming you're on a budget, i'd get the S&S unless you can score some good used TOGs
