Well I think need and positional value are different, so it's important to keep that perspective. Our biggest need at the moment is probably C because Skura is a gamble, whereas Jesse Davis is a competent RT with a few years left in the tank. So getting a C this year to cut his teeth under Skura and then take over in 2022 is probably the more immediate need. But the C position is a good round less important than the OT position. Given that RT is Tua's blindside, I'd say that long term RT is the bigger need, and clearly the higher positional value.
So, from my perspective, we should be looking at good but not elite OT prospects in round 2, with an eye towards preferring pass pro over run blocking because it will be Tua's blindside. We can take a less polished prospect since Davis gives us some time, but I'm looking at the #36 or #50 picks to get an OT that is good but not elite. Using those same picks on a C, I'd expect a truly elite player. You mention Creed Humphrey (my C#1) and Quinn Meinerz (my OG#1) as possible interior offensive line prospects, and those happen to be the two I like the most. Meinzerz can play C and Humphrey can play G, so they have the positional flexibility we require. If we could get either of those guys, I'd be ecstatic. But if both are available at #36 and I see a good OT, I'm taking the OT, because the position is just so much more important. Guys like Liam Eichenberg or Jalen Mayfield are not elite OT prospects, but I'd be happy with either at #36, and if one is available at #50 we should take him. If a kid like Christian Darrisaw or Sam Cosmi slips to #36, it's a no brainer, but I can't see Darrisaw falling that far.
I agree with both
@Nublar7 and the OP
@fastball83 that the C and RT positions are what we should be looking to get. But if Quinn Meinerz slides to #50 or lower, I'm taking him even if we already have a C or T.