I fingerpick exclusively, acoustic and electric, and I don't grow my nails too long - just a little bit longer than usual (you probably wouldn't notice unless you looked closely), and only on the index finger and middle finger of my right hand (I don't use my thumbnail, just the actual thumb itself). You don't need to go the whole nine yards with growing your nails - just allow them to get a teensy bit of extra length to make picking that little bit easier (and they're easier to keep clean this way).