The resurrection of the dead is composed of the soul of the body re-animating the physical matter of the body, in order to stand in General Judgment before all the world, publicly exhibiting God's justice before all mankind. There is no contradiction here as you suppose. Meanwhile, you have yet to explain the presence of the elders and myriads of martyrs in Heaven *before* the end of the world as described in Revelation 7, as I've cited in detail in other posts.
Regarding the elders, I said that we only know of 3 people who are in heaven. If you can name some more, list 'em. Those folks are sure there as you mention, but we don't know who they are and where they came from, do we? The Catholics don't use the title "elder" anyhow, so we can rule them out :)