Personally, I had little problem even running the 250ohm 990s, but it could vary from phone to phone depending on the in build amp. Pretty sure you'll be fine with the 80ohm model.

Regarding your second question, on android I recommend Wavelet as an equalizer. Just pull down the ~5k-10k frequencies to your liking. Wavelet also comes with pre-made equalizer curves for many headphones, also worth a try