Boeing is probably not a good aspirant company. Even though both companies manufacture airplanes, S&S Air manufactures small airplanes, while Boeing manufactures large, commercial aircraft. These are two different markets. Additionally, Boeing is heavily involved in the defense industry, as well as Boeing Capital, which finances airplanes.
Bombardier is a Canadian company that builds business jets, short-range airliners and fire-fighting amphibious aircraft and also provides defense-related services. It is the third largest commercial aircraft manufacturer in the world. Embraer is a Brazilian manufacturer than manufactures commercial, military, and corporate airplanes. Additionally, the Brazilian government is a part owner of the company. Bombardier and Embraer are probably not good aspirant companies because of the diverse range of products and manufacture of larger aircraft.
Cirrus is the world's second largest manufacturer of single-engine, piston-powered aircraft. Its SR22 is the world's best selling plane in its class. The company is noted for its innovative small aircraft and is a good aspirant company.
Cessna is a well known manufacturer of small airplanes. The company produces business jets, freight- and passenger-hauling utility Caravans, personal and small-business single engine pistons. It may be a good aspirant company, however, its products could be considered too broad and diversified since S&S Air produces only small personal airplanes.