Blur Plugins

I'm not aware of any specific plug-in that can add these filters, but there are some Elements add-ons that can do so.  See, for example, ElementsXXL.

What exactly do you want to do.  With a little bit of work, Elements can do most of what these filters can.  I guess it depends on how sophisticated you want the filter to be.  I suspect that for most Elements users, the Guided Edit>Depth of Field tool is sufficient.

It can't really add a specular Bokeh but you can always paint that in manually in Expert mode.