I guess I should introduce myself

[pocaracas]

They become the best brothers when their ages are close... 2 to 3 years is good.
The difficulty some find with sleeping at night often comes due to them sleeping during the day.
The second one can become easier, because you'll have an extra hand to help a bit (the older brother)... On the other hand, he may get jealous, making things complicated.

In the end, their personalities will define how they behave. Good luck!