Sigg water bottles are very widely used in Europe, the dents , scratches and war wound are signs of 'proper' use. The more battered the Sigg the greater respect for the drinker. !
As long as you get the water bottles (and not the almost identical fuel bottles) then you wont get the aliuminium taint and no sigg bottle should ever leak unless the washer at the top is missing (easily replaceable in any good mountain store or by an elastic band)