I've just completed the classical section of an excellent self-study course that has familiarized me with the fundamentals of music theory, including scales, keys, intervals, chords, nonharmonic tones, cadences, figured bass, Roman numeral analysis, chord progressions, modulations, and voice-leading principles. I'm especially happy with what I've learned about traditional four-part voice leading, including voice ranges, inversions, doubling, objectionable motion, and how to connect scale degrees. I've taken extensive notes, and I'm confident in my ability to use these notes to perform analysis and to check voice leading for "correctness" according to the norms of the common practice period.
However, the course has given me no experience generating original melodies or harmonies of any length. Since my purpose in learning is to become a composer and producer of original music, (music for video games, as well as pop music) getting such experience is very important to me. I would like a solid grounding in classical techiques, and I don't want to move on to the jazz section of this music theory course until I've written some classical music. It seems, based on the way the course has stressed four-part voice leading, that I should focus on writing (or at least harmonizing the melodies of) some Bach-style four-part chorales.
I don't have money for an instructor, so I'm wondering if anyone can point me to a workbook that would provide some kind of direction and/or a framework for writing chorales? I really like the style of the book Composing Music, by William Russo, because it is made up almost exclusively of writing exercises presented within extremely limited bounds, giving the student only a few creative options at a time so as not to overwhelm him or her. However, Russo's workbook is not focused on chorales, and I haven't found one that is. My research has turned up the following resources:
The Study of Counterpoint, by Alfred Mann
Harmony, by Walter Piston
Counterpoint, by Walter Piston
Harmony & Voice Leading, by Carl Schachter and Edward Aldwell
Preliminary Exercises in Counterpoint, by Arnold Schoenberg
Counterpoint in Composition, by Felix Salzer and Carl Schacter
Counterpoint, by Knud Jeppesen
Fundamentals of Music Composition, by Arnold Schoenberg
The Complete Musician, by Steven G. Laitz (actually, this one is probably too expensive for me right now)
Four-Part Chorals of J.S. Bach, by Charles Sanford Terry (already planning on buying this one, unless there's a better edition)
If a workbook of the type I'm looking for does not exist, which one of these books should I start with, taking into account the style of instruction I'm partial to, my level of experience, and my goal of doing some kind of original classical writing as soon as possible?
Any input would be appreciated. Thanks in advance!