I think you can use any thread weight you want as long as you use it with the appropriate size and type of needle. You may also need to adjust upper (and possibly bobbin) tension for the thread. Probably the first thing you want to do is choose a thread that has the "heft" to it that you want, then choose the needle, then experiment with tension settings.
This book likely contains information that would be of use to you:
http://www.amazon.com/Machine-Quilti.../dp/1564772160