phrase usage - "need + verb-ing" vs "need + [to be] + verb-ed"

1 That sofa needs cleaning again.

2 That sofa needs to be cleaned again.

Which of the above senteces sounds more natural? And, is "to be" always needed in structures like 2, as, for example, in:

2/a You need your head examined.

2/b You need your head to be examined.