I don't think you were asking about the timing cover as much as the end seals on the intake. The timing cover cork is easy
End seals for the intake, there are two camps.
1 - Ditch the end seals and use an adhesive sealant, Ford makes one, Motorcraft TA-31. Regular RTV won't last. LOTS of guys go this route successfully, but I have not ever done it
2 - Glue the corks down, but to do so they have to fit. This is what I do, I use 3M to solidly glue the corks to the block, then at asselbly, give them a light coat of any RTV. It acts as a lubricant to allow the intake to slide while you tighten it, then hardens to seal
#1 likely takes less thinking and works for some very smart guys, so I can't knock it, but you are counting on a bond, not pressure, to hold a seal and hold it in place
#2 often doesn't work well if the block or intake has been cut, and often you need to cut the intake to get the proper room, or sometimes you have too much room. However, I like it because when I am done, I am done. The cork is held tightly in place by both compression and adhesive.
I would likely recommend #1 if inexperienced at this
Finally, which gasket doesn't matter as much as you think, just pick one, Mr Gasket 202A if you need us to pick. The key thing is making sure it all fits together and you don't rush
Second thing, you HAVE to check every bolt in your new intake. Almost every single FE intake takes different length bolts from the others, and if you have too long of a bolt, you'll push out the threads and if too short you will strip it as you torque it.
What I do is, stick all my bolts in the holes with the intake on the bench, you want about 1/2 inch sticking out. If I have at least that, then I check the depth holes in the head with a small screwdriver to make sure none will bottom out
