I would strongly advise you to by one in rather than have a litter, it is a big responsibility to find loving permanent homes for puppies. People who say they want one when you mention it suddenly find all sorts of reasons not to have one when they are ready to go. Advertising means you may know nothing about the potential buyers.
You could also put your bitch at risk, particularly if she is small. She may need a c section if she is unable to give birth naturally, and this could cost hundreds of pounts and you might even lose the bitch and puppies. You have tried twice, maybe it is not meant to be, so go find yourself a lovely new baby and enjoy without all the trauma of breeding.