I don't think that this quilt works well with fabrics that vary a lot. If it would be suitable for fussy cutting then it might not work well. Most of the pieces are cut fairly small so think about the variation you would get between 1 or 1.5 inch pieces of your fabrics. As with a OBW, the effect of the fabrics will be more their color values and motif size.
I've seen it done well both including a few fabrics that read as blenders, to give the eyes a place to rest, as we as without any blenders for a busier effect.
I started with my first few fabrics when I made mine, then choose more fabrics as I went along. Making one or two sample 9-patches and then laying them on the fabric bolts was helpful as I went along.