Welcome. I went for the rizoma rad guard which has been unbelievable quality. I've fitted it to both the streetfighters I've owned and I've done about 20000 miles worth of riding combining the both bikes and its like new. Evo tec tail tidy's the one. I think you have the spacers in wrong if the seat wont fit on after tightening. I found the same problem and it took ages to get the spacers in the right order. Hope this helps.
