This trip is combination of unique cultural and religious, which is a unique trip among numbers trekking trail of the Nepal.
First of all I would like to inform you, for the Manaslu Circuit Trek, you need minimum 2 people in a Group for this trip, which is you already know. And require special permit for the Manaslu Restricted Area (provide by only Government Register Trekking agency) and at list you need one Government License holder trekking Guide. And as this is a restricted area trip, you need 4 different permits, which are following below:
[I] MCAP (Manaslu Conservation Area Project) Trekking,
[II] ACAP (Annapurna Conservation Area Project) permits,
[III] Manaslu Restricted Area Trekking Permit
[IV] TIMS Cards ( Trekkers Information Management System)
While organizing those permits, the immigration office asking for your Nepal visa which must be validate entire trip and original passport with 4 copy of PP Size pictures each of you. To make those permits, it takes almost whole one day to make different office.
You can extend or make shorten the trip as you wish. We are happy to offer the services as have requested; whether it is a package or just the Guiding and porter service. I assume, you quite fit for this trek. Probably, you have some previous trekking experience in mountain. Even though, for none trekking experience trekkers also can do this trip due to starts from low elevation and goes gradually again the elevation. The mountain scenery is stunting and unique live hood of High Mountains are really interested. This trip will bond us with local people to seek their culture, tradition, belief have been centuries.
Regarding, porter; of course, if you are able to carry all your bags why you spend money for the porter. But you will find your trip huge difference using porters and not. Some time if while you carrying your bags by own, you may miss some exclusive picture shut or cannot fully enjoy such a beautiful nature. So, I also would like recommend you, if your budgets will able support, than it will be batter to hire a porter to fulfill you dream in real.
Manslu Circuit Trek can do 12 days in shortest time, which is known as Rapid Manaslu Circuit Trip. But I would like to recommend you 16 days Trip for Manaslu Circuit or you can add some days than you may visit Sacred Tsum Valley as well in 21 days trek. To explore most of attractions of Manaslu Circuit via Tsum Valley need minimum 19 days to above 26 days. Here is Trek Itinerary with different services and it cost below:
16 Days Manaslu Circuit Trek Suggested Itinerary