Harold,
High Quality chocolate will really help with High Quality results.
Take a look at Callebeaut TV. It's free and they have a lot of good content.
To answer this specific questions, go to http://www.callebaut.com/uken/callebaut-tv/tutorials/the-basics-of-working-with-chocolate/choosing-the-liquidity-of-your-chocolate
this video discusses viscosity of chocolate and how it will affect your results.
Some of the differences between the chocolate chips you used and a good couveture chocolate will be the particle size, cocoa butter content, and I'm not sure what else. Essentially chocolate chips are designed to retain thier form at high heat. They can have a larger particle size because the other ingredients associated with chocolate chips i.e. flour has a much larger particle size and you wouldn't taste the texture difference.
Anyway, I'm not sure which chocolate is best. I'd play with some callebeaut or valhrona to start with.
You may also enjoy the Chocolate Apprentice blog. It is written by a lady who took the Ecole Chocolot course. It is fun to read about her expiriments, successes, and opportunties for imporovement.
Did you order the wybauw book yet?
Have a great day!
Larry