YAY! Im very excited for you
Sounds like you have nearly everything you need for Poppy's arrival.
I think you should get her a carrier/crate to carry her in for vets visits though, I didnt get Poppy one and at the moment its difficult to take her places in the car as I always need someone with me to hold her while I drive.. so I have a carrier in the post from Ebay but you can buy a pretty pink one from Pets at Home.
Pets at home told me the best food for my Poppy was Wainwrights so I have the wet and the dry versions of the chicken and rice and I am in the process of getting her onto dry only.
Also about the puppy milk... I bought Poppy puppy milk when I first brought her home and noticed she drank all the milk but didnt eat any of her food so I think it was lying quite heavy on her stomach.. when she had her vets visit they told me I shouldnt be giving her milk at that age (6 weeks) because she has already been weaned off her mammys milk and it could give her the runs. So they told me just to give her water and I noticed her stools were much better and she started eating her dinner properly.
I have a kitten harness from Pets at Home for Poppy as its the only one that will fit her (shes 10 weeks and just over 1 pound) so you could try one of those as I find the xsmall harnesses are still too big.
Other then that sounds like you have everything sorted
cant wait to see photos!