Others on this thread have identified the better housings. The best method to finalize your choice is to get to a consumer dive show , or DEMA and hold each one and work the controls. This will make the choice for you.
""BUNA O-Ring, Size 2-209." If you can not locate o-rings at a plumbing store then your local hardware store, Lowes, Home Depot, ACE, OSH sell them in one-packs from Danco # 95. (The size is 15/16 X 11/16 x 1/8)."