Re: Buying pumps now or later
Basically, if you are determined to BF, you will need a pump eventually.
If you are a FTWM, then its good to invest in a good electric dual pump. This is because you have limited time to pump at work. If you use a single pump, you need lets say 15min per side plus massage time plus wash up time = 45-60 mins each time for pumping. You need to pump 2-3 times a day while at work so that works out to be 1.5-2h for 2 times and 2.25-3hours for 3 times. Take this out of a normal working day of lets say 9hrs. I think you get my point. If you have a dual pump, you express both at the same time, so prob less can settle in less than half and hour for each pumping session.
If you are a SAHM, then it depends on whether you latch on or you express. If you latch on fully, then a manual pump or single pump may suffice for those times when you need to express after latching or when you are out away from baby or those night feeds that your kid has dropped. If you express fully, then get a good dual pump as even though you are at home, spending the time pumping means not being able to do other things.
The best pumps (excluding those big hospital ones) around are generally Avent Isis (is it Isis or Iris?), Medela Freestyle, Medela PISA and Ameda. These are the "hospital grade" pumps that are suitable for consumer's own use. The rest of the pumps generally do not have the technology that helps to stimulate milk production. Which one you choose is up to personal suitability.
Before you buy a pump, do consider the situation where you are pumping. Important to consider where you are going to be pumping at work - is there a power supply? If there isn't, then no need to think, go for the freestyle coz the others need power supply. Freestyle is based on rechargable battery (not ordinary kind ok.. its their special kind). Also consider the weight of the pump and how you travel as if you are taking MRT/bus to work, you may not want to carry a pump that is too heavy and bulky (please remember that you need the pump + cooler bag).
Whether to buy now or later depends on what you are buying & whether it is easy to get. One pitfall to breastfeeding is the unavailability of a good pump to aid you in clearing your milk effectively during the inital days when milk comes in, hence leading to engorgement & pain which makes people give up.
Don't worry about milk supply. Like I've said many times. If you are willing to put in the effort and are determined enough, there are ways to increase milk supply. No milk seldom exist - its actually just lazy mum.
For myself, I bought a Medela PISA before the birth of my #1. Its a great pump but I could not tarhan the weight and bulkiness. I only brought it out once after confinement & I realised that since I take MRT to/from work then, I would be too tired from the weight of the pump. So I sold it off and bought a Freestyle which I have been using ever since. No regrets as even when I am out of office, I can simply find any clean toilet/ nursing room (even without power source) / empty room to express. The handsfree is great too as I can continue to do work while pumping. Just wash hands, set up, let the pump do the pumping while I work (I brought readings/laptop to the nursing room), stop and wash up.
Re: Cup Size & Milk
No relation between cup size and milk. A cup also can have a lot of milk. But underwire can cause blocked ducts... so get bras without wire.