The amount of effort depends on the level of preparation and thought you put into the start of the site. You should have a clear end goal, and as many details as possible. With that in place you just kneed to know enough about the available WordPress functions so you can choose which is right for your set of options.
The first part of your question is simple: Yes WordPress can be used to create a site like that. The second part isn’t a yes/no answer and varies as I mentioned in the first paragraph.
If I were going to design a site similar to that, I would probably make sure to utilize the WordPress Categories, Tags, Custom Post Types, then plan a strategy for listing them.
Here are a few good links to the features mentioned:
(Using WordPress Taxonomies, Tags, and Categories for a product directory):
http://www.leewillis.co.uk/wordpress-taxonomies-to-create-a-product-directory/
A Plugin to let Admin’s or Everyone to preview the themes:
http://wordpress.org/extend/plugins/nkthemeswitch/
A good place to get help if you get stuck on a WordPress related task:
https://wordpress.stackexchange.com/
I hope that helps you out. I’ve learned my lessons the hard way. The best Advise I can give you is to plan out the required features and make a solid plan on executing them. This should save you a lot of time and back-stepping.