Looking for a plugin as a starting point for modification

Hello,

I am pretty new to using WordPress. I have been given the task of looking for a certain plugin but my search so far has been fruitless.

The site I am working on is pretty normal, using Shopp plugin. It has a catalogue page, product page, add to cart button and cart page. I need to find a plugin that will add these features to this site:

1. When I hover my mouse over the link to cart page, it shows a mini cart (not a new window but just a small square box which shows the summary of items in the cart and their price, and a link to the checkout page).

2. Top level menu which, when I hover over its submenu, displays an image beside it. I should be able to set which images are to be displays for each submenu from the backend.

Does anyone know if there’s any plugin that could provide a good starting point for me to implement these features? (I have a beginner~moderate level of skill in PHP)

Thank you