advice repotting cattleya warnereii and BLC Ahchung Ruby

[snowberry]

Hi Orchid friends,
I am an amateur grower. Last year I acquired a cattleya warnerii and a BLC Ahchung Ruby. Both are putting out new growth. I wonder though if I should be repotting them. The cattleya warnerii has many roots outside the pot. The BLC Ahchung Ruby topples over in its present pot. Also what potting mixture should I use? What size pot(s) should I aim for?