I went to my local library and found a copy of Integrated Korean: Beginning 1 (2nd Edition.) I've checked it out and I'm almost done with it, only two chapters left.
I had heard about this textbook before, but I shied away from it, because I heard it was better used in a classroom setting. Yes, there are exercises in this textbook where they ask you to do things with your classmates, but those can easily be done on your own or just skipped; there aren't many of those.
In addition, KLEAR supplied audio for all the chapters in the textbook here: http://kleartextbook.com/b_beginning/a_audio-files/beginning-audio-lesson-1-5/
The only downside is that there is no answer key for this book, but the problems shouldn't be too difficult and can mostly be checked with examples from earlier pages.
I created a Memrise course for all the vocabulary in this book, found here: http://www.memrise.com/course/965804/integrated-korean-beginning-1-2nd-edition/
There was one that already existed, but some of the audio for it started getting pretty bad. The audio I used for this course is from Naver.
I've taken to doing a lesson a week. Each chapter is divided into two parts, each of the parts introduces new vocabulary and grammar lessons. Monday and Tuesday is the first part of the chapter. Wednesday is the second block of vocabulary and some more grammar lessons. Thursday and Friday are finishing up the chapter, with Friday usually being the "Usage" lessons and exercises day.
You can honestly do more than one lesson per week, sometimes I find myself finishing too quickly, so you can easily speed through this book if you want.