On our tour we will enter Iran from Armenia probably in December and want to visit Oman as well. So we are planning to go to UAE and Oman from Iran via ferry (bandar lengeh/dubai or bandar abbas sharia) and afterwards back to iran to continue our trip towards Turkmenistan, Usbekistan etc.
As we exit Iran we need to get a new visa to re-enter Iran about one month later.
Does anybody know how this is done best? Embassy in Muscat or General Consulate in Dubai?
And do they give you a new visa again after just one month?

Thank you very much!
Jonas
P.S.: Not a visa question: are there any problems booking two-way ferry tickets (2passengers and car) when you take the ferry back one month later?