None. Welling on a rogue = under 40% success rate unless you have super good gear. But if you have super good gear then you should just make a magician and use it on there
I'd say you have a much better chance of finding good items from just climbing your character
but that's my opinion. If you're really interested though, level 64 is the best for welling. You can check out my guide to welling on a mage if you want:
http://forums.d2jsp.org/index.php?showtopic=30551054&f=74