i have a couple of avent bottle as i am starting to express for a few feeds... Noah takes to it fine and i like the bottles (good quality plastic etc). I did find the teat (even newbon) allowed himt o feed quite fast and I have had pigeon teats recommended to try (i think it is the slow teat). this will fit the avent bottle too.
I also have the avent iQ UNO electric pump and I have found it fantastic - v easy to use etc
I dont have a steriliser as I dont express much (yet) - I just wash and boil the equipment and bottles... I have also bought some Milton which I can use to sterilise. I think I will get a steriliser eventually though.