Came across these on my local hardware store website while looking for something else.
http://www.toplinemullingarhardware.ie/kitchen-and-bathroom/kitchen/kitchen-cookware/glassware/kilner-drinks-dispenser-5-litre
I imagine there are a number of uses these could be put to but naturally conditioning might be one. They "might" be strong enough to condition in and then just pour from the tap. Great for small batches.
Also in woodies: http://www.woodiesdiy.com/product/kilner-5ltr-drinks-dispenser-/35303/11
there's an 8 litre version here: http://www.cookware.ie/shop/bottling-preserving/8-litre-kilner-drinks-dispenser/
I have the 8 litre one, don't think it would be strong enough to condition in. Plus you have to open the lid to dispense. Great for serving cocktails in though.
There's so much surface area that if they'd probably pop or crack with any pressure.