For our second hatch we used White Leghorn eggs from ebay. I'd read that they laid a good sized white egg and I was keen to add that to our flock. Unfortunately, out of 6 eggs we had 4 successfully hatched but only one was a female. We named her Buffy. She is quite dopey and is in the bottom 3 hens of the pecking order. She has an awesome floppy comb though and will follow us around. I was a bit dissappointed to start with as she laid the smallest eggs we've ever had but after 4 months she started laying 55g eggs which was much better. She's a small hen so I doubt she will lay much bigger eggs.
The Leghorn is a British rare breed and you can read more about them on the Rare Breeds Survival Trust website. Leghorns were actually developed in Italy and became popular in America for the white eggs that they lay. They came to the UK from America in 1870. They come in a variety of colours but all have yellow legs and white earlobes. They don't often go broody but are good winter layers, one of the more prolific rare breed chickens.