The Iranian mullahs had no interest in good relations with the US, and would have rejected the USSR. They hated both, but hated the US more.
There is a fallacy that many nations or groups who are opposed to the US are just waiting for us to be nice the right way.
I believe that history shows most groups and countries are on courses that are only somewhat influenced by the US but are primarily self-motivated.
I think a very fair way to look at the mullahs and the ayatollah is that they were deeply embittered over the loss of status and privelage at the hand of the Shah when he broke up the feudal holdings and power of the mullahs. The ayatollah was personally bitter over the death of his son during this.
They took advantage of the popular discontent resulting from the Shah's lack of popular support to offer what they claimed would be a return to a great Islamic utopia, but of course have delivered a theocratic hightmare, as all theocracies tend to be.
The US, if it had not existed, would have had to have been created. What good is a theocracy without a great satan?
Ed