I would format the existing server and then install SBS 2008 natively. SBS 2008 and Exchange are installed on the same server by default. You will need a 3rd party SMS Gateway for Exchange to deliver SMS messages. You should not install Outlook on the SBS server this is usually not a good idea. You can install SQL Express on the SBS server which is free. If you already have a SQL server then writing to it directly will be up to the 3rd Party software. As far as BizSpark is concerned, you just have to meet there licensing requirements, I believe. As far as step by step guide for installing exchange it is pretty straightforward as it is installed during the SBS install and is all wizard based. But if you need something I could get you a link that might be helpful.
Hope this helps.
