A couple things,
The grammar in your "sasou" example is wrong. "Sasou" is a transitive verb which means it always has to have a direct object. This is important especially in Japanese where there are different verbs with the same meaning, but differ with respect to whether or not they are transitive/intransitive. Eg. "Chiru vs. Chirasu", which both mean "to scatter/disperse".
So "Kare wa watashi ga sasotta" is grammatically wrong. If you're saying "I invited him", it'd be "Watashi wa/ga kare o sasotta".
A better example might be "Watashi ga (kare ni) sasowareta" vs. "Kare wa watashi o sasotta", where in the first sentence, "I" am the subject, and "am invited" (passive, so both transitive and intransitive verbs can be used iirc), "by him", while in the second sentence, as you posted, "He", the topic, "invites ME" (direct object, marked with "wo", necessary for using "sasou" in the active voice as a transitive verb).
Also, not sure about "iretemasu". Shouldn't it be "ireraremasu" if it's "ireru" in its potential form?
Additionally, one should note that "go" and "o" aren't used interchangeably. Very often "Go-" precedes chinese-origin words, while "o-" precedes those of Japanese origin. For instance, "o-" precedes i-adjectives in polite speech, since all i-adjectives are of Japanese origin, while "go-" precedes most na-adjectives, since most na-adjectives are of Chinese origin, though some do take "o-".