Here's what Mobot has to say about 'Morning Light' blooms:

"Tiny reddish-copper flowers appear in long tassel-like inflorescences above the foliage in mid to late September, gradually turning into silvery white plumes as the seeds mature. Blooms later than most Miscanthus cultivars. Flower plumes persist well into winter providing good winter interest."

Google Images has lots of photos of both grasses in bloom.

Consider the timing of the bloom on both. 'Morning Light' blooms a good deal later than 'Graziella'.

Bluestem Nursery's website has a photo gallery with some great seasonal grass combination pictures you might check. There are some real good ideas to see on it.

I have found these progression type shots on garden blogs, but don't have a site, I just run across them now and then. I usually type in the variety of grass, hit images and go through the Google sites page after page.

That John Greenlee book on grasses also has some good combination shots and is available in the library and also many photos on his website.

Also, try typing in Piet Oudolf for some really fantastic grass-scapes for which he is famous worldwide.