If you want to add a clientside mod that isn't on your list, follow this guide:

Step 1:

Navigate to your .minecraft's config folder.

Step 2:

Open the "Serversync folder"

Step 3:

Open "serversync-client.cfg" (If windows asks for a file to open it, you can just use notepad.)

Inside of the config, you can see how i've disabled certain mods from being deleted. Simply add your mod in the same way. For example, if you have a mod called AlkiasTheBest.jar, add the line "mods/AlkiasTheBest.jar" to the end, then hit save.