The wing size will be driven by the exposure protection you use, and the weight you carry to offset that. Remember, the wing should be sized to float your rig (without you in it) at the surface. Integrated weights (if you use them) are in that equation then. Exposure protection compression at depth then leads to the weight you use needing to be offset by the wing.
The 18# Oxy (and similar - I dive a VDH) is like wearing nothing, and I use it for warm water and a 3mm shorty. The 23# and the 30# are also very nice as the long and narrow design rides the tank nicely. We use the 30# in cold water with steel tanks. At your height the Oxy/VDH/DiveRite is a great option in my personal opinion.
The 18# Oxy (and similar - I dive a VDH) is like wearing nothing, and I use it for warm water and a 3mm shorty. The 23# and the 30# are also very nice as the long and narrow design rides the tank nicely. We use the 30# in cold water with steel tanks. At your height the Oxy/VDH/DiveRite is a great option in my personal opinion.