There are others far more knowledgeable about the ins and outs of patching than I, but I would say definitely go ahead and patch. I always dl patches before I start playing...less 'bugs' and worry.
As for HoW...haven't heard it's out of circulation (doesn't make sense that it would be, really). I had a little difficulty finding it, (turned out not because it was out of print but so popular it sold off the shelf before I even saw it there!) so I ended up ordering it through our local Hastings Booksellers (online at
www.gohasting.com or stores if you have one). Have you tried to order it thru any bookstores like Barnes & Nobles (do they do pc games?) It's there, you just have to find it before everyone else!