Sachin, I tend to get mine from a store in Singapore but from where you are, the easiest is mail order from Smoooth Drag. They are very efficient and you can pay online. Try
http://www.smoothdrag.com/In terms of washer life, I can't tell you I think would need a few years to be able to comment on this. I do servcie the drag of my reels after every trip and what I can say is I have not noticed any wear on them to date. When it comes to a choice of reels, it really is a personal thing. I cannot say that I think the 10000 is a superior reel to the Saltiga and vice versa. They will both do the job.
The Dogfight will pair up as well as any with any popping rod. I don't generally use my WV but I do run the Dogfight on my SP78-UHL.
While you can use the 20000 or Expedition for popping, you just have to work that little bit harder. It's not really a problem but if it is a lure that needs to be worked fast, it can be hard work. It is a compromise - if the reel is primarily for popping, I'd suggest the faster ratio reel but if you wanted to use it primarily for jigging, then I'd opt for the lower ratio reel.