this is the gasket you need, it goes between the header and cat, the old header should have one see if you can use it and if you can reuse the factory manifold gasket as well if its in good condition, as far as the egr tube this is what i did
remove all the manifold bolts,
loosen the two nuts at the bottom almost all the way,
now pull the manifold away from the block,
line up and tighten (by hand) the nut from the egr tube,
push the manifold back on and put 1 bolt on each corner (4 bolts) dont tighten all the way,
install the rest of the manifold bolts and tighten in proper order and spec