For recording yourself, the line 6 audio interfaces work great with no noticable latency. I use the GX but am considering upgrading to the KB version if/when I start putting songs together.
For mixing your guitar, a mic and sending that combined signal through a webcam for lessons with Pebber the mixing board / sound card option might be the way to go. I don't have that setup. While the quality of sound that I get in my house is great, when I Skype with Pebber he says it sucks. In fairness though, the quality I get back from him isn't perfect either (and it gets to my ears through my audio interface and powered speakers), so internet connectivity and/or Skype software could be a limiting factor as well.