Is my fermenter big enough?

[eulipion2]

Hello,
I'm getting ready to make an oaked blueberry mead (recipe here), which calls for 12 pounds of honey and 2 pounds of blueberries for five gallons, then, in secondary add another 1.5 pounds of honey and 8 pounds of blueberries. Would a 6 gallon fermenter be big enough for the secondary step? If no, what's the smallest I should even consider? Do Better Bottles come in sizes larger than 6 gallons?

Thanks in advance.

 

[eulipion2]

In addition, I always see/read/hear to use a bucket for primary and glass for secondary. Can you do that in reverse without any negative effects? Is there a reason not to use a plastic bucket as a secondary? For maturation I'd move it back to glass, but I'm really trying to avoid spending a big chunk of (non-existent) change on a new large glass carboy plus shipping.