Re: Original or remastered effects?
OP, Everything you've said says "Buy the originals" to me. It's what I own. I'll not get into a big argument here about the new effects. There are plenty of threads about them. You are investing money, and while it might be nice to see the new effects (try youtube compilations) they - to me - jarringly interrupt the viewing, they look SO different from what was do-able then; and so different (clearly animated) from the rest of the footage. You asked advice; there it is; I wish you very well.
I didn't find them jarring, I just didn't find them very good sometimes. It seemed like they should've brought in a professional director to handle the composition of the shots.
"...the most elementary and valuable statement in science, the beginning of wisdom, is I do not know." - Lt. Commander Data, "Where Silence Has Lease"