Just a note on using glass carboys for primary fermentation -- bigger seems to be better (I would kill to have a 14 gal. demi-john like Janx!) for a couple reasons. First of all, the smaller the carboy, the smaller the batch you can brew. When I was starting out, all I had was one 5 gal carboy, and I would rack from it after primary into a bucket, clean it, then rack back into it. Then I bought a second 5er, so I could rack straight from one to the other (much easier, and safer). But the problem I had was that after accounting for the space taken up by trub at the bottom of the primary, and the blowoff from the top durring ferment, I would only end up with 4 1/2 gallons of finished beer, or even less. I then bought a 6 gal for primary, and when I racked into the 5 gal secondary, I was able to fill it all the way up, ensuring maximum batch size. The other issue is directly tied to blowoff. From everything I have heard, you loose some of your hop flavor if the carboy gets totally full of krausen and has to shoot some of it out of a blowoff hose (as my last batch did with a vengance), not to mention lost beer volume. (I have also been lead to understand that there might be some benefit from blowoff, something to do with eliminating hangover causing elements, but I'm not too sure). I was lucky enough to get a 6.5 gal given to me lately, and intend to start using that for my primary, to minimize how much beer and hop stuff is pushed out of the top.
