I found these amazing Anita maternity bras which actually have an underwire. I'm a dd cup and got very bad back aches from maternity bras for DD1 and DD2. Once I wore underwire maternity bras for DS1 I actually found them so comfortable it didn't bother me that I had to wear them all the time. I found I had to wear maternity bras until I weaned my kids (all between 13 and 15 months) as it was just easier.
At night I found laleche feeding bras the most comfortable (kind of like a sports top but a cross over at the front). I personally couldn't get comfortable in the bonds maternity singlets. I was also told by a midwife to wear very supportive feeding tops in the first few days or weeks as the milk is getting established as this can help prevent mastitis.
I also bought the cotton nursing pads for nighttime to save a bit of money. Avent make them.