I wouldn't stress too much about it. Everyone I know that's had cancer or heart disease was breast fed.

If you are really concerned about it you could get the Happy Baby glass bottles. They are the only ones I know of. They are available at Coles.

I think that the supposed issue with the plastic ones is to do with heat. If you don't heat the bottles then the risk should be reduced. I feed Brock his formula at room temp (used to warm it but found I didn't need to). I use sterilising solution from Safeway so I'm not boiling them or microwaving them both of which could damage the plastic.