Found some clamp on (1 1/4") highway pegs and wondering if I can simply clamp them onto my frame? Or should I be looking for the bolt on/plate mounted style?

 

I guess you could if you found you could still get a comfortable position to mount them. They will probably scratch or mark up your paint unless you add a crash bar and mount them to that.

Why don't you get the harley ones that bolt in. I use them with the mini footpegs harley just came out with, very comfy.