Why not get another good egg-laying breed of pullet? Yeah, leghorns are great layers and all, but there are PLENTY of breeds that are not bred exclusively for hard and fast egg production and will lay over a longer period so you get a better distribution of the eggs. With leghorns it is more like the cartoons with a pile of eggs pouring from the chicken (they might have more egg follicles than say a delaware or black australorp, but it still won't be well distributed).
If you want the white chicken, white rocks could be a possibility - they will be much friendlier than a leghorn (they are less lanky than the leghorns so in my personal opinion are prettier, anyway!). For white egg production, you could try brown leghorns. For excellent brown egg production, black australorps.
I know my barred rocks in their first year laid 6 eggs a day (out of 7 hens) and we were literally giving them to everyone who would take them. Now at 2.5yrs they are not laying as much and we have to supplement with purchased eggs, but getting two new pullets each year would keep you going if you're in for personal egg production.
Either way, good luck. It would be really expensive (feed- and time-wise) to order 20 roosters to find that they were all sexed correctly. I would also seriously reconsider buying a ton of roosters unless you are willing to kill them yourself. Do you have a dog or cat you could feed the roosters to, if you're not willing to eat them yourself?
