Get a Desantis Scorpion kydex IWB. Very comfortable, very stable and very secure. Extremely thin profile and the weight is distributed all the way around your hip. It's an open bottom holster so it will fit any size 1911.
I can easily conceal a Glock 20 under a normal fitting shirt so a single stack micro 1911 should be a piece of cake.
Regarding the issue of carrying a pistol in hot, humid weather, allow me to give you some advice. You're much better off with a moisture wicking compression under shirt and a lightweight synthetic blend button down. It might sound counter intuitive to wear two shirts in hot weather, but believe me, it works. I've been carrying a pistol in hot, sticky weather for 15 years and it's much cooler and more comfortable than a tee shirt.