The 16-15-3 would work well with a 3S pack, or a 16-15-4 for slighly lower rpms. I use a 16-15-4 with 3S packs for mild performance and 4S for higher performance using a Jazz 55 esc on my collective-pitch Corona and it works very well. I used a 35amp CC esc previously and it worked well... until I goofed up the polarity on a micro deans connector with a SmartBEC- not so smart.

If a motor says it will draw 25amps under full load, that most likely refers to laboratory conditions with light loading. A 25amp esc will probably handle it most of the time. Once mounted to the crutch and enclosed under a canopy, airflow may not be ideal so pushing the outer limits of what the esc can handle may not contribute to a reliable setup. Go with the next size up. Also, consider that you may change your motor and battery setup down the road and perhaps wish you had gone with the next size up from that. So with that in mind, get at least the 35 or the 45. Anything smaller than a 35amp esc for a Corona-sized bird limits your options.