All grasses bloom. That's how plants reproduce themselves....by producing flowers, then seeds and all will attempt to do so at some point in their life cycle. Some OG's are less inclined to produce flowers/seedheads routinely and some will produce flowers/seedheads that are barely noticeable but all will attempt to go through their normal reproduction cycle at some point.

Taller growing OG's -- Miscanthus, Panicums, Calamagrostis, etc. -- tend to have more noticeable blooms than a lot of shorter growing grasses or sedges. And they are pretty reliable in producing them every season......the flower plumes/seedheads are one of the primary features folks grow them for!

I don't know what OG to suggest for you as I doubt it exists. There are some grass-like plants that produce flowers very infrequently (phormiums, bamboos) but they are unlikely to be appropriate for your purpose either due to lack of hardiness or height and vigor. You can cut off the budding flowers as they become apparent but that's not easy to do with affecting the natural appearance of the grass.

Have you seen this "non-blooming" grass somewhere? Can you post photos? That could help with an ID.