For 2 of my trips I bought a WDW scrapbook to use and love them because of the graphics on the front. The first was an 8.5x11 and it worked fine -- regular refills of that size worked without a problem. The second was a 12x12 and finding refills was a pain! Since it was a 3ring style I was able to simply take all of the refills out and put all of the same size/type in. (which was a bit of a waste of money as well as not perfect because they were a bit too long for the book -- it worked well enough, but not perfect). Anyway, I am now going to simply use the same style of scrapbook that I use for my day-to-day albums - simply going to get it in red and have the cover embossed at my LSS (local scrapbook store).
From what I have read, the scrapbook supplies in Disney are mainly limited to papers and stickers and other 'flat' items, so getting them home is not a problem. I am lucky that several stores around me carry Disney-themed items for scrapbooks, so I mainly shop there. There are many on-line companies that sell Disney scrapbooking supplies, so that is an option as well. One that I like particularly well is:
http://www.mousememories.com/
As for memorablia -- Everyone needs to make a decision as to how concerned they will be with acid-free and such. Personally, it is more important for *me* to include maps, postcards, tickets, napkins, etc. in my books than to leave them out because they may not be "archival quality." Now, I am careful how I use them and try to not rest these items against actual photographs by using pocket pages, memorablia sleeves, acid-free (sometimes also buffered) matting papers, etc.
I love scrapping my Disney trips -- probably my favorite theme to scrap!! Have fun with it!
HTH!
JenC