It would be nice if the company used the 76 for newhires as a last resort (same type rating, same instructors, until recently same sims), but it's a mishmash.
No way to know what the future holds.
Would avoid 777 as just not much flexibility in that system for someone with young kids. (Biggest $$'s though, so if there's a lot of familial support for CinCHaus could be more of a player. But 15 days gone is tough)
Would avoid the Bus, Bidpack is shrinking. One big spike in fuel prices and I could see us parking quite a few. Which can be great.
76 is growing, and WB pay. Haven't looked at the bidpacks, but think your relative Seniority would be similar 75 or 76. My expectation is more of the Senior FOs are already in a WB or laying over at home in the 75. Wouldn't expect many of them to transition to the 76, some will because it's an easy transition from the 75. Upgrade to the bigger bucks 777, yes. 75 Capt, yes.
Hope your parents chose your lucky numbers wisely.
Good Luck