Minkulus, so sorry.
I was in almost exactly your position nearly seven years ago, when my DCs were 8 and three. We were all living overseas when DH died suddenly, and I had to deal with all the nightmare bureaucracy of post mortems and getting permission to repatriate his body to the UK. It took nearly a month to arrange the funeral in the end.
Do you have anyone to help with the bureaucracy? DH's colleagues in the overseas office were incredibly helpful - does your DH's employer have anyone else on the ground out there? The embassy/consulate also went out of theirway to be helpful, though it probably helped that a lot of them knew him personally.
To be honest, looking back, I think that having the bureaucracy and organisation (we had to move back to the UK because if his death, so at the same time as the funeral stuff I was also sorting out schools and somewhere to live) to focus on was what kept me going rather than collapsing in a heap.
As far as the children are concerned, what mine seemed to want was as much normality as possible. Their worlds had been turned upside down, and everything was going to change, so the routines of going to school etc seemed to be a comfort to them. I second Winston's Wish for advice, and you might find the Merry Widow discussion board useful for support - it was set up for young widows/widowers.
I'll be back with more later, but I just wantto say that bleak as everything seems now, you and the children will get through this and be OK.