Repotting seriously overgrown plants (including a few walkerianas)

[Dekejis]

So I've got several plants that I've received that have really really overgrown their pots - most of them are Cattleya walkerianas (although the most overgrown is a Mini Purple). I've heard that this is good for walkerianas, but I'm wondering when do you go ahead and pot up? I've got some baskets I was considering potting these guys up into, but they all have copious roots hanging out in the air (one of my concerns is that they are heavy enough now to tip over and break those roots, which has happened a bit) - should I repot these guys, and if so, should I add media to the basket? I don't want to suffocate the aerial roots either.
Thanks!