Drummingman
Goju Ryu is only the Higashiona lineage (Naha Te) with additions made by Miyagi and then whatever is added by the branch you are interested in. If you are affiliating with the IOGKF or another association based in Okinawa it will be close to the original.
Shito Ryu has the Higashionna kata (Naha Te) but also has the Itosu lineage kata (Shuri Te).
Naha Te is noted for its smooth and flowing technique as well as its rooted and heavy stances making for very powerful technique, thus these are the characteristics of Goju Ryu (and Uechi Ryu and Ryuei Ryu). Shuri Te is characterized by quick techniques and higher/ lighter stances. As Shito Ryu is a combination of both, it retains both types of kata. Typically the Naha Te kata are done a little lighter and faster than Goju Ryu and the Shuri Te kata are done with a little more heaviness than many of the Shorin Ryu (Shuri Te) schools.
Naha, Shuri and Tomari are the three regions of Okinawa. Each had its own way of doing things and slightly different lineages. Before the term karate was used, the term Te was used to describe martial arts in Okinawa. Thus, each region's art was referred to as Naha Te, Shuri Te, and Tomari Te. However, the bunkai (the hidden self defense techniques within the kata) of the kata of all of the styles will have many similarities. Typically, in the old days, the direction one went in their training had a lot to do with their body type. If you were bigger/ heavier and powerful you were recommended to go the Naha Te direction. If you were smaller/ thinner/ quicker then the Shuri Te lineages might be for you. Today, it doesn't really matter...each school will have something for everyone.
Its hard to answer these questions on a forum...there is too much detail that gets missed. Its much easier in person. Stop by. I don't care if you want to train at our dojo or not. I'll give you very unbiased information on all of the styles you are interested in. My training for nearly 20 years has given me a good perspective of most systems. We can figure out what is best for you. Style. philosphy, location must all be considered when selecting a dojo. It is my responsiblility to do what is best for you...not me.
Talk to you soon
Rob