I got a kit with a couple of the avent bottles in it as well as the microwave steriliser. I also brought a few of those S26 readymade tetra packs of formula to keep in the cupboard jic. I found the bottles were also handy for cooled boiled water, esp seeing as we were heading into summer. I was adament that I was going to breastfeed but didn't want to be running all over town to get formula and bottles in case of emergency.
My DD never had a problem with going between teats and my nipples, I put it down to giving her the water in a bottle as well as the occasional formula feed when I had to go out. (Had huge troubles expressing).
I have found the Avent bottles and teats great. And my sister used the Avent manual pump and has had no problems. I would say an electric one would be better due to it being quicker and easier on the old arm muscles.

Good luck