I am very familiar with the Eagle rod as we used them in lots engines.
Not many were boosted to be completely honest though. Like about our IHRA record setter, we beat the CRAP out of those rods and they took everything we threw at them. Again, this was a drag race situation, not street (std Eagle bolts for what it's worth).
6.200 is a long rod for sure (ours were std 5.7 Chevy length rods) I believe they will live. I don't think the statement about the thickness makes much difference though as an I-beam Oliver is thinner than a 1/4" in the I-Beam (again I am very familiar with this rod too).
It sounds to me like you want someone to talk you into buying the Olivers not out of it? To that end, you absolutely cannot go wrong with an Oliver rod!
I think either will work to be honest. I plan to use Eagles in my LS when I get to that point. I built race engines for 15 years before my career change if that helps... PM me if you want to discuss that further.
Chris