onion: I've said pretty much the same stuff on here before, but I think you may as well just enjoy your remaining time off without trying to introduce a 'substitute'. I am saying this with the benefit of hindsight, but I found that very little of what I tried to do to prepare DD actually worked.
She adapted herself, when in a nursery environment. When I was there, she thought it was ridiculous to try the cups/bottles and completely rejected them.
In fact, DD seemed pretty distressed by any attempts to give her breast milk by any means other than directly from the source. So we had to bite the bullet when she went to nursery: she drank some water in the day and then fell upon me as soon as I picked her up.
I can't pretend; it was pretty tough at first. She wasn't happy. But things improved quickly and we are still breastfeeding at nearly 20 months.
Please, please enjoy the rest of your maternity leave. I spoiled the end of mine by fretting so very much about choosing to carry on breastfeeding.
Are you planning on carrying on feeding yourself? I've done it both ways: I weaned DS off at around 9 months (which I suppose I regret, although he settled in pretty easily), and carried on with DD (again, mixed results, but ultimately a better appraoch for me).
Good luck x