help with choosing the right skimmer

[vince0]

hi all, im in the process of planning a new reef 90g with a 45g sump. im curious as to wether i need to include amount of water in the sump when choosing a skimmer. to simplify should i look for a skimmer with a 100g capacity or 150g? Also, i am new to salt water and im curious as to wether anyone could recomend any specific brand/type of skimmer over another.

thanks in advance,

vince