Congratulations on your baby and the choice to breastfeed!!!
If you go plastic, make sure they are BPA free. That's the big no-no. If it doesn't SAY BPA free... it isn't.
I liked the Medela bottles. I exclusively breastfed and tried to do the bottle thing when we were out...but that didn't last long. Quite honestly, lugging bottles around was a pain. So I just nursed in public. Now, granted, we were living in Germany at the time and by the time we moved home my daughter was older and not nursing every 2 hours. But, if we have another child ... I plan to do the same.
I just found having to wash the bottles, pump the milk, blah blah blah was so time consuming and tedious. I'm a SAHM, so there wasn't a NEED to pump.
I know I know I know... people here can be very ..... stupid about nursing mothers. But, I could typically find a quiet place and we could do it undisturbed.
I think if you're not using a bottle regularly, then having the special ones to reduce gas isn't going to make that much of a difference. In addition, babies can get gas even if you nurse. My daughter has colic/gas issues and she hardly ever used a bottle. If you run into those problems....
www.coliccalm.com
MARVELOUS! Seriously. Miracle drops.
Good luck!