JLex Comments and other Joomla extensions compatibility

Hello,

I used to have Artisteer and thinking of joining you guys again if moving my infrastructure to Joomla.

I will be using some third party extensions such as CC Comments or JLexComments but their appearance is not quite up to scratch.
Will I be able to use NicePage to change the look of their modules?

Also, can I change the look of email notifications whether generated by Joomla or by third party extensions such s the above?

Many thanks, Sabin