Hey there! My son is 3 weeks today, and he's probably close to 10 lbs. I started with disposables at birth, 8 lbs 11 oz, but only used them for 4 days cause of leaks. I bought newborn prefolds cause I was scared of the fitteds being too big in the beginning, and have small sandys and MEOS. Yes, the MEOS look big and fluffy, but they are wonderful, and you dont worry about leaks. I dont even have them, or the AF covers, on the tightest snaps. They dont have to fit tight to work, which is another plus- they look so comfy! Especially if you think you'll have a bigger baby, you wont have any problem getting them to fit from birth. Word of advice though- dont buy any little pants or anything "fitted" cause their bottoms are pretty big and probably wont fit. My son was already out of NB clothes at 2 weeks.
I love my small sandys too, actually, I like them a little better. But, cause of money, I'll probably stick to OS after he outgrows the small sandys. He outgrew the prefolds pretty quick, and they leaked a few times... and I didnt need them after all.
I'll be happy to email you pics of my son in his OS- just let me know!
Hope this helps you!