Island Peak vs Mera Peak vs Manaslu Circuit vs ...

Hi,

I'm looking into going on a trek this month or in April, I am looking for something challenging, with high altitude, peak climbing if possible, and that is feasible without too much technical mountaineering skills.

I have considered Island Peak Climb via EBC, Mera Peak, and Manaslu circuit.

For the first two, several guides say no technical mountaineering skills are required, some say Mera is slightly easier, others say I need some mountaineering skills. Manaslu seems like a very cool cultural experience as well, although it wouldn't bring much challenge, and I would also like to develop some mountaineering skills.

Therefore I'm a little lost in what to choose, and would appreciate any insights on what Island and Mera peaks are like technically, and/or thoughts on other treks to do, not necessarily in Nepal.

This is my experience:

- I have climbed Kilimanjaro last year, Northern Circuit Route. Didn't specifically prepare physically for it. I felt the biggest challenging to be the altitude/breathing.

- I have climbed Mount Baker last year. I trained for about a month mostly doing stair-stepper with a backpack. I felt the biggest challenges to be learning rescue techniques, ascenders/descenders, and also the 45lbs weight of the backpack. Was also pretty scared of crossing crevasses and the like.

- I am also a runner (including marathon distance) and a hiker.

Thank you in advance!