32 - 35mm road tires, no flat protection nonsense, 60 psi. supple ride, shock absorbing, if they're any slower than regular road tires it will be unnoticeable, volume = low pressure with no pinch flats, low pressure = no punctures.
Skinny Gatorskins, Randonneurs, and the like are for people who are trying to use the wrong tire width for what they're doing. Wide Gatorskins, Randonneurs, etc. are for people who don't know they're unnecessary. I mean the what you have will be fine now that you have it, it's just a tire and I'm overly opinionated, but try something else next time.
Randos are tight, but if you're having
that much trouble with mounting the tire you're probably doing it wrong. Make sure the tire is in the lowest part of the tirewell all the way around instead of sitting up at the hook. This will give you more to work with on the opposite side where you need it. See photo: If the bead is down in the center as opposed to at the edges, you get a few more mm to work with.
no metal levers ever. even if they're covered in something to be nonmarring, you want your levers to fail before you bend the rim
source: I ride a pretty gnarly gravel section a few times a week on my commute and have done pretty extensive loaded touring on the stuff. also opinions from wheel and tire engineers
ETA actual recommendations:
Resist Nomads in 35mm sizeway are cheap and good.