I Have A Biblical Question on Organ & Tissue Donation-Christians ONLY!?

I feel compelled to donate organs and tissues when I die just as I donate blood now and wish to donate marrow (though I hear its a rather painful procedure). However, I was wondering what the KJV Bible has to say about these donations. Before I make my end of life issues known, I was wondering if a Christian could provide me with some scriptural guidance as to what to do about this. Also, what does the Bible have to say about cremation and burial of a coffin. Idk which one to choose but I want to be biblical correct. Thank you.