Setting up wireless network on large estate - recommendations on setup, bandwidth and hardware

Hi,

I have been tasked with setting up a wireless network at my employers large estate. Requirement is that all rooms be able to have wireless access throughout the year and that the network be able to accommodate conference users every two years.

I have attached a file that outlines the estate and the approximate distances to the office. Currently there are two residential Time Warner Road Runner high speed cable internet lines (max 5mbps each) One going to the office #26 and one going to room #15.

The rooms are hardly ever full throughout the year, typically a max 3-5 (10 people) of them are only used at any one time during the year.

However every 2 years a big conference is held on the estate - all rooms are full and people also come from nearby hotels and need internet access to get at emails, etc. The conference usually hosts 70 people but I would say we can safely half that amount for those trying to get on the internet at any one time.

I have phoned Time Warner and we can get a Business (15mbps) Line on the estate and that this could possibly coexist with the current two residential lines. What I am thinking is getting the business line into room #15 (this has to be the permanent main line as it is under contract) and then getting the two current residential lines re-cabled to #42 and #31 or thereabouts (these are month to month contract lines and only firing these up when the conference comes round)

My questions:

1. Do you think the above strategy is any good?
2. Do you think we will have enough available bandwidth to support a max of 35 simultaneous connections?
3. If so how do I mange all 3 seperate connections and pass people off to the next router if one is maxed out?
4. what type of hardware would you reccommend using and where would I place them so the whole estate is lit up?

Am I missing anything? Budget is not really a big issue.......

Many Thanks
Neil