I like the sizes that you've posted... width is something I sorely want on my tank.  I like the idea of an external overflow and an opened top (well, as opened as possible).  I like black backgrounds, but others may not like it as much... so I would leave that as an option.  I assume you'll be drilling holes as requested as well? 
 
-Richer 
		
	
		
		
		
		
		
	
		
		
	
	
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