Alot of the new issues have the same coin, same mint mark, but one unc
and one proof. Do you guys think both are need for a collection, or
just one example?

I would concentrate on the proofs because they are the more specialized item
and thus a higher collectible value. If fact I have read comments here about
historical appreciation of silver proofs...

Also, why not have twenty or more proofs of the same item...you know like
Goldfinger ?

One problem is that the proofs will show imperfections that are either on
the coin or on the holder. And it seems to me that there were lots of
imperfections on the L&C proofs...