I see you have 50 posts, so welcome to Audioholics, and please take the replies in this thread as a learning experience, and not as being ganged up on.
I understand where you're going with this, and yes, technically silver is a better conductor.
I must say that in actual practice, when it's high cost is considered, the benefits of silver speaker wire doesn't really pan out.
If there really was a benefit, the utilities companies would use it to offset their massive power transmission costs. Instead, they use the less conductive aluminum in (most, not all) of their delivery process.
The answer is to use the next size larger copper wire, at a fraction of the cost of silver.
In regards to banana plugs, don't worry about too many connection points. Simply use an Anti-oxidant like this:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=341-200