Hi
I recently made a liner for my Moses Basket.  I decided NOT to make it padded as it makes it less breathable and I was worried about SIDS etc.  So I just made it out of a light cotton fabric.  It looked GREAT.
But here is an easy pattern for a padded one 
link
I can't help you in regards to making it for you however, but you should just go and see a dressmaker