Cheap jars - google catering suppliers. I've bought loads of stuff of the internet very cheaply.
Where to sell initially? You could try a FB page to start with.
That last question, I have no idea.
Whilst you have a lovely recipe there, have you thought about
a) what is your USP - there are loads of lovely jars of stuff to sell - what makes yours different?
b) One recipe is not going to sustain a huge business for very long - have you got stuff to add?