Hi Richard,
Correct, I don't need both, but there isn't a simple override to a query by classname AND document Guid (at least not on my version of v7).
After some digging, i did find an override that will suit my needs (query a single document by guid):
TreeNode node = treeProvider.SelectSingleNode(CMSContext.CurrentSiteName, null, CMSContext.CurrentDocument.DocumentCulture, true, "Custom.Profile", string.Format("NodeGuid ='{0}'", guid), null, -1, true, null);
A bit of a 'hand-full' of unneeded arguments, any chance of a SelectSingleDocument(Guid guid) override in future releases?
Cheers,
P.