Aryae,
You should remember that small peptide binds less CBB than larger one, thus smaller peptides are harder to detect. If you really want to see your peptide on the gel, you can try to load more (or try other detection method). Changing the gel % won't help you here, unless you think your peptide migrated out of the gel.
If you are going to use western anyway (which is way more sensitive detection method) why bother with the gel staining?
Cheers,