Thank you all for your replies and advice.
After speaking to my HV today, they said the decision was entirely ours, but that she though that he may be a bit young to go into a normal bed.
So after a lot of thought, we decided to go with the air bed. It is just a transition and when he is older, we will get a bed (saving a few pennys for now
)
He went down fairly easily in it tonight, he cried out a few times, and only took about 15 mintues to settle, and he seems to be fine.
Here is a pic of him in his new bed.
Thanks again for all your advice.
Paula x