Search the docs to see if there is a binding for the outlets you plan on purchasing (e.g. if looking at outlests from Yeelight, search for “yeelight”). If not then the outlet is probably not compatible. If so, open the binding README (should be the first link in the results) and see if it has a list of explicitly supported devices or a list of explicitly not supported devices. If there is no list then the binding should work with any device from that company/technology (e.g. zwave).
It does not.
If you are OK with a little DIY/modification then search the forum for the technology/company and see if someone has posted about an alternative firmware you can upload onto the device to make it talk MQTT. For example the Sonoff devices from ITEAD can be flashed with Tasmota. Most ESP8266 based devices should similarly be flashable.
Such a single list is simply not feasible. There are over 300 technologies and APIs officially supported and each of those can support hundreds if not thousands of individual device models. And new models are being added every day. The amount of work to create and maintain such a list is huge, the benefit is dubious (do you really need to list all the TRÅDFRI device models when the TRÅDFRI binding supports ALL TRÅDFRI devices?