Outdoor Rooms/Landscaping concepts

Time to consider our options with the landscaping of our outdoor area.  I have been looking through magazines, trawling through the net and visited some display homes to get some ideas of what we can do.
From the alfresco to the back fence we have an area of 4m by 7m.  We'll be extending the alfresco to the back fence to make this one large outdoor area, ending up with a total of 7m by 7m of outdoor space.  Of course, the alfresco is already under the original roof and we want to add a pergola from the end of the alfresco to the fence.  The paving/concreting will be extended from the alfresco to the fence as well, maintaining one consistent level.  I want to incorporate our BBQ into this space.  We should end up with a large enough area to also have a seating area similar to the pictures below.

This is similar to what we want done from the alfresco
to the fence.

This is another option for extending the area to the
fence.

Alfresco and seating area 

Side of outdoor area

I would ideally like to have some walls built along the fence, like the pictures below, and have them wide enough to provide additional seating.  

Like these feature wall panels

Seating incorporated into the wall

Along the side of the house, we decided the best option at this stage is to use stepping stones and pebbles, like the pictures below.

Will be getting some decorative wall panels to use as features in our outdoor area.  

Now that we have a good idea of what we need, the big question is, how much is all this going to cost?  We're prepared to do some of the work ourselves, especially the building of the pergola, we've done it before.  Will definitely need someone to do the flooring and walls though.  Time to get some quotes.