yes, this can be done with power store.
the best strategy would be to install power store to it;s own directory:
for example, this way you retain your existing index page and only need to giv a link to the store directory.
in power store, the admin panel has a design editor that lets you choose from 4 existing themes and edit those themes to change colors and fonts an such.
there is also a content management system so you can edit the content of the store pages, and a product catalog management system to allow adding new products and categories,