20 amps ESC can be used for 2205 2300kv motors with 5 inches propellers. They are also compatible with motors that smaller than 2205 or slower than 2300kv. For example 2204 2300kv, 2206 1900kv (with 5 inch propellers).
If you are using 30amps ESCs, you should choose motors that are bigger than 2205 or faster than 2300kv, and propellers should be bigger than 5 inches. For examples 30 amps is required for the 2204 2700kv, 2204 3200kv, 2205 2700kv or 2206 1900kv(with 6 inch propellers).
35 Amp ESCs is required when you are using 6s lipo battery for your rc model.
and if you need 30 A ESC, you can view this review of Tattu ESC above
If you wanna buy it, here is Germany shop: http://www.gensace.de/tattu-esc-30a-blheli-s-2-5s-w-dshot-no-bec-prototype-1161.html