Yes, Jazz In Silhouette is a great album of Sun Ra, at a time he was still very close to the dominant style of that time, the hard bop, and in the same time already "somewhere else" (and not only because he was alone - and stays alone - to play this style in big band).
But the universe of Sun Ra is more vast than that particular records: Other Planes Of There, The Magic City, Atlantis, Space Is The Place (the vidence one), The Heliocentric Worlds Of Sun Ra (vol 1 specially), Nothing His, Les Nuits de la Fondation Maeght (LPs on the French label Shandar, out of print), Disco 3000 and Sunrise In Different Dimensions, are some of my favorite (but you may like others) and all show how unique this band and how great and out of proportion the genius of the Sun Ra was.
It seems to me that today, Sun Ra doesn't get the recognition the man and his work (from swing and bop to the new thing and back) deserve.