I have gotten excellent interview audio just using the internals on the Sony PCM-M10--like recording outdoors, sitting on a bench on a hillside, with the PCM-M10 on the bench a foot or two from the person speaking. Both sides of the dialogue came through very clearly, along with the birds singing.
The Sony mic inputs are also fine with mics clipped to lapels using the 1/8" input. I have used Sound Pros BMC-2 and lately Church Audio CA-14 cardioids. I put them both on the person being interviewed, so my questions are somewhat quieter (esp. with the cardioids) but still clear. If you take a stereo pair and clip one to you and one to the interviewee, you'll get a pretty annoying left-ear-right-ear dialogue, though of course you could fix that in post-production.
It really depends on what you mean by good quality. If you want radio-station quiet, you need to record in a quiet place. But a lot of journalists get their interviews with the built-ins on Sonys or Edirols. (I've never used a Zoom, but you'll find complaints about noisy mic inputs from H2 and H4. You should try your H1--record, say, a watch or clock ticking with internal and external mics.)
Personally I don't think you need to go for the class of equipment that uses XLR, because something like the PCM-M10 has all the fidelity you need. Voice recording is a relatively narrow spectrum of frequencies and dynamics. With current equipment, where you record and microphone placement (close enough to the speaker to avoid room echo or background noise, not so close you hear heavy breathing or popped Ps), are going to be far more crucial to the recording than the recorder itself, as long as it has a passable mic input.