Drupal group pages

We are creating a ‘light' social network with the Drupal CMS and require a system of allowing users to create a ‘group' homepage which can be used to post news, image galleries and discussions similar to http://teamsugar.com/group/230676

Specifications:

Authenticated Drupal users use a web form to apply to create a group page, including an oursite.com/path, a leading image to appear on it, and an ‘about us' snippet of text to accompany.

The Drupal administrators then moderate that user's application and create the group page for them.
When the page is activated, the user should see a menu visible within their admin page to manage their group.

Group ‘owner' functions
Group owners have the ability to do the following:
Upload a leading image (like the one on the left-hand side of the Team Sugar site)
Write a short caption to explain what the group is about (also appearing on the left of the screen)
Write a post, which will appear as an update, like the Team Sugar site.
Create an image gallery, and upload images to it.
Moderate group memberships, submitted by other users

Group ‘member' functions
Anonymous and authenticated users which view the group page (visible at ourdomain.com/groupname) cannot view discussions and other members- to do so, they must select a link which says ‘Join this Group'.
Once the group ‘owner' moderates the user, that user can participate in the group's discussions and see the group's members. They can also upload images to galleries the group ‘owner' has created.

Group affiliation:
Groups can also ‘affiliate' with other groups.
When the owner of one group is viewing the page of another group, they will be able to see a link entitled ‘Affiliate with this group' (which appears just below the Join This Group link, but is invisible to users who are not group owners).
When the link is selected, the owner of that other group receives a request.
When the request is moderated by the other group owner, the affiliated groups appear within a block entitled ‘Affiliated groups'.

Two more specifications:
A group owner can ‘appoint' a member of their group into the same role as them, to administrate the group
A user can apply to create more than one group, and can ‘own' several at a time.

Drupal user pages
Authenticated users can also have their own page, which has the same features of group pages, which have the same requirements, except:
Users can have one page only. A user must be authenticated and have a user page before they can apply for a group page
In addition to joining groups, users can also ‘affiliate' with each other. The groups users are members of, and friends they are affiliated with are invisible to users who are not affiliated with them.
Users can upload image galleries and post blogs, but discussions appear on their pages in the form of standard comments, which they are able to moderate themselves.
User pages will be powered by a different template to group pages. I am using taxonomy theme, so this shouldn't be an issue.

Finally...
I am hoping that despite these specifications, the functions can be created using existing Drupal modules (I envisage using Organic Groups, CCK, and Drupal access roles). Simplicity is key, so these specifications aren't strict, if you can think of a more simple way of achieving the desired results.

I would appreciate a good timeframe and cost for making this happen. The design of the templates is not important at this time – these will be organised later. What is important now is that the modules are correctly configured to work in the way described. Please let me know if this is too big an ask – I am hoping it isn't, and I have just been too long-winded in describing the functions!