I'm going to create a fairly large (from my point of view anyway) web project with a friend. We will create a site with roads and other road related info.

Our calculations is that we will have around 100k items in our database. Each item will contain some information like location, name etc. (about 30 thing each). We are counting on having a few hundred thousand unique visitors per month.

The 100k items and their locations (that will be searchable) will be the main part of the page but we will also have some articles, comments, news and later on some more social functions (accounts, forums, picture uploads etc.).

We were going to use Google AppEngine to develop our project since it is really scalable and free (at least for a while). But I'm actually starting to doubt that AppEngine is right for us. It seems to be for webbapps and not sites like ours.

Which system (language/framework etc.) would you guys recommend us to use? It doesn't really mater if we know the language since before (we like learning new stuff) but it would be good if it's something that is future proof.