Originally, we started building a massive directory site using eDirectory, but the framework is extremely difficult for web developers to work with. My question is this.... would Silverstripe be a good solution for building out a site that allow the user to search and view about 1000 business listings in a variety of categories? Then we would need the ability for businesses to "claim" the listing and and pay for upgraded features. Then there would be a separate admin interface for businesses to log into.

Any info would be greatly appreciated.

Yes, SilverStripe would be well suited to this. Have a look at the wiki pages about the SilverStripe datamodel.

Also, the new ModelAdmin features of 2.3 would be very useful for administration of the listings.

Thanks for the response! By the ModelAdmin, what are you referring to? I'm very new to all of this... do you mean that I can use the CMS view as a way for my 1000 business owners to edit their listing and upgrade features, etc?

Not quite.

ModelAdmin is a tool for site administrators to easily view, modify and add records (ie, through forms or by importing CSV files).

For your users you would need to create the appropriate views and actions, but this is straight forward with the sapphire engine.

Some resources:

Creating your model: http://doc.silverstripe.com/doku.php?id=datamodel

Creating forms: http://doc.silverstripe.com/doku.php?id=recipes:forms

Are you a web developer yourself?

Thanks for the info. Yeah, I'm a web developer, but I'm pretty new to Silverstripe and things like it.