I'm 5' 6", and I like big bags, too. I've tried a few 35 Birkins lately, and don't find them too big for me at all...in fact, I could go 40, but the weight may bother me. Since you have another 2.5 inches on me, and like big bags, too, I reckon you would love a 40! Can you go to a store and try some on? This is the only way I have discovered a 30cm is too small for me, otherwise I was considering this size, and may have ordered on online only to regret it later.....