Originally Posted by
Litespud
If you're anyway handy, you could elongate the slot in the lower clamp plate to give yourself more range. It's likely aluminum, so a Dremel or circular file will go through it easily
Aluminum can develop stress risers at any scratch or grind if it is a stressed part. It is new post time and I would go with a two bolt type. Make sure is can be adjusted from below.
I use a Nitto S83, but the Ritchey Classic,the VeloORANGE Grand Cru Long Setback, or Thomson Elite Setback were my other choices. From the images you posted you will want a post with setback as you are already past the max setback marking on your seat rails. The Nitto S83 is 20mm setback, The Ritchey is 25mm, the VeloOrange is 30mm, and the Thomson is 16mm.