Are you planing on using them for wine (long term storage) or beer (shorter term storage)?
Wine and long term beer storage works best in glass, but can be done in high quality plastic (Better Bottles).
For shorter terms (most beers), food grade plastic is fine and generally much cheaper.
Brewing is science, math, chemistry, biochemics, horticulture and culinary arts rolled into one, yet comes out to become a beautiful smooth sensual thing that brings out the idiot in everyone! - kybar