I only used bottles when I expressed to leave my boys with sitters etc. My boys took anything so I have used lots of different bottles. Never had a problem with Avent and used the Avent steriliser for everything, you don't need the steriliser to be the same brand as the bottles in my experience. I do really like the Tommee Tippee Closer to Nature bottles. There is a pump that goes with that and it is supposed to be good but I haven't tried it. Pigeon ones are good too. They have pigeon, medela and TT at the Chemist Warehouse.
I froze breast milk in ice cube trays so I liked wide neck bottles better as the cubes fitted through the neck of the bottle.