your choice
As much time as you took to type that out neatly, you already know the answer you are just looking for support. Both ways are probably the right decision, just pick the one you desire more.
The salary is fine, they are paying for a very expensive type rating and I would bet you'd get reasonable raises in the future. If not you'll be very marketable in a year or two as a strong FO ready to upgrade at the right time with another company.
You will be away a lot more than your current job, however I would bet you'll get some sort of scheduled time off which compensates for that.
Again, do what your gut tells you and have fun....you are in a great position, don't waste the opportunity if it's what you want.
good luck