Bert's right. SBS typically has the same RAM limit as the Standard Version of the Server. SBS 2011/Server 2008R2 Standard both have 32GB limits. Same was true for SBS 2008/Server 2008.
You're thinking of Server 2008 Foundation which had an 8GB RAM limit. It's not really part of the SBS line.
If you do not require SharePoint or Exchange, SBS 2011 Essentials may be better suited to your needs. On SBS Standard, high amounts of RAM make sense because it will utilize it all. With SBS Essentials, it probably idles around 2-3GB. I'd say 12GB is more than enough for Essentials. 16GB is good for standard. Anything more would be better.
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