Stamp Collecting

Hi, my 11 year old niece has asked for a stamp collecting book and some stamps for Christmas. I thought this would be simple but there’s more options for buying stamp sets than I thought!

Where sells the books that you can stick the stamps in? We don’t want one that’s very childish but also not one that looks like it belonged to Great Grandma?

I thought WHSmith (or whatever it’s now called) or Collins would have them but they don’t and the Post Office ones aren’t great. Where else could I try? Ta