Yes, this is right. Most of the draft analysis I read think there are at least four and maybe six starting, first round caliber, OT prospects in this draft. I don't think a trade up will be necessary, and depending on how the board falls they may be able to pick one up while dropping back a few spots.
I don't think it is ever a reach to draft a tackle in the first round. Outside QB there is no greater positional value than a player who will be on the field for every offensive snap and is likely to be a part of your team for ten years.