Had one of the WSN Tiger before. I think the barrel length is slightly shorter, but definitely not as bad as the HL Tiger. Personally, I'll leave it alone.

As for metal track, I'm not sure whether it'll fit, but even if it is possible, I don't advise you doing it - the stock plastic gearbox is too weak and not enough power. You'll have BIG problem running it with metal track anywhere except smooth surfaces.