You probably can start researching on the big ticket items first as it normally takes a longer decision process (i.e. cot beds/strollers/breast pumps etc.) As you step into your second trimester, it is the best time to shop around to compare the prices.
As for milk bottles, to be honest, it depends on your little darling so no need to really stock up just yet. Personally, I had to keep changing brands for my baby until I found one that reduced her colic and the nipples were just soft and slow enough for her...she (and of course, me and hubby) finally managed to sleep through the night without much crying and screaming after that.
Meanwhile, just to share, I am helping mummies to ship in baby products from USA at prices 50% off retail prices for most items. Do drop by my thread http://www.mummysg.com/forums/f81/45...ge-bags-87527/ or my blog www.babyswonderful.blogspot.com when you are doing your research.