The second as in these phrases may be translated cuanto, cuantos, or these words may be used to translate both the first and the second as.
I will buy you as much (as many) as you need.
Te compraré cuanto (cuantos) le hacen falta.
(c) As soon as may be translated literally tan pronto como, but it is also very frequently rendered así que, en cuanto, or luego que.
You are going to do it as soon as you know what I am going to tell you.
Lo vas a hacer en cuanto sepas lo que yo te voy a decir.
—LOS QUINTERO.
As soon as night had closed in, they went again to the judge's house.
Así que se cerró la noche se dirigieron otra vez a la casa del juez.
—PALACIO VALDÉS.