How about a self-patterning yarn? Paton's Soy Wool Stripes (can't find a retailer online, but popular craft store Michaels carries this yarn) is a yarn that can be hard to work with as it's not plied, so it's off-limits to crocheters, but you, as a knitter, may love it. A crochet-friendly yarn that self-patterns is Lily's Sugar'n Cream, which comes in Solids/Prints, Stripes,
(differently-colored plies). Lily's yarn is also cheap as dirt, maybe even cheaper. :P
If you're looking for yarn that knits up into a material with an interesting texture, you're getting farther away from solid stitch definition and ease of use.
Also, on another note, please don't sell products you knit from free patterns, unless you have the explicit permission of the pattern's creator, or it says somewhere in the pattern that you may sell their product. Most pattern creators prefer you don't.