I heard Onesies Downunder is a good place for pacifiers and onesies in you're willing to pay the shipping from Australia. If not, there are tons of Etsy shops that sell them. BigTot is the name of a good U.S. Etsy shop (I think).
I don't have any pacifiers but my sippy cups and the like have all come from amazon. I love the Nuk trainer cups, they are the perfect mix of bottle and sippy cup. They have a silicone nipple but it is a spout like a sippy cup so you still have to apply the tounge pressure to get anything out but it handles more like a standard sippy. I get any new toys from there too. I mostly collect the toys I had or would have had as a child but if the mood strikes me for something new or I need to give gift ideas to the hubby its amazon all the way. I don't know if they have onesies though. I am currently working on making a "little" wardrobe for myself but it's going to take a while I have to grade up toddler clothing which takes a lot of work and measuring.