I'm in a similar boat... Looking to do more 'serious' recording on my iPad, but I have either Apple earbuds or some AudioTechnica headphones that sound decent for listening to music, but not recording.
I'm debating whether a cheap (under $200) set of monitors would be better or a similar cost set of headphones...
Go for the monitors. It feels much more natural when mixing and doing playback. Larger drivers mean better bass reproduction than with cans.