customizing widgets

Hello,
I’ve been trying to find a plugin that would allow me to customize the comment section on my blog (or other widgets for that matter, such as categories where I would like to change the default order), i.e. that if a user submits his/her URL it would not show on my site. Another feature I would like to see is to have the name link to a portion of my blog without saying “name on page/post” it should ideally be “name [linking to page/post]: with the first few words of the comment”.

Anyone have any ideas?

Thanks,

Markus