Buying full manga collections (in English)

Hi,

I really like reading manga, but my Japanese level isn't good enough to comfortably read manga's in Japanese. I was wondering if anybody knows any places in Osaka/near Osaka, or on the internet, where I can buy full manga collections in English. I don't want to buy individual manga's because there's nothing worse than starting a series, liking it and then not finding a certain book. I'm very interested in finding the full Rurouni Kenshin collection in English. I've tried Amazon Japan, but they only have individual books