Jessica, I continue to pray for your hubby and will keep doing so until he comes home with you!
As for the funeral, you plan what you want to honor Matthew. He is your son and you know him better than anyone. Don't let your MIL railroad you into doing something you don't want to.
As for Nickolas, pamper him like nothing else on his birthday. Do whatever he wants to do. I think the movies is a great idea. He'll always understand the circumstances behind his 14th birthday and if you make it an awesome day despite those circumstances, he will remember a mother that bent over backwards to make his day special even with all the stress that you've been carrying during this time.
I'm praying for you and hoping that amid all this, you can find some peace.