I own both Jurassic park and Monster Bash, and I am married with 3 kids. Here's my advice:

Firstly, try to play as many pins as possible and narrow it down. If it isn't possible to play them, try to watch online videos, read about the rule sets, and look up reviews. It seems like you have already done this a bit, but you seem to have questioned MB also...so I would say make very sure beforehand, since pins aren't cheap.

Second, buy what appeals to you the most...not the kids, wife, or friends. You are the one buying it and will likely be playing it the most, not anyone else. Buying family friendly pinballs is good, just make sure you love it first. Kids and wives lose interest fast.

Lastly, I really don't recommend buying NIB. I suggest getting a HUO game to save money. I find that HUO games from collectors cost far less and are better playing already because they are dialed in. Every pin will need maintenance somewhere down the line, so find a reputable tech in your area. If you have a few tools on hand and a willingness to do small fixes, that doesn't hurt either.

Having said all that, here are my specific recommendations for the two games (and more recent titles):

A JP pro's average price according to pinside is 5200, and a premium is 7200. A classic MB is 7000 and a monster bash remake LE is 7700. If you just need to clip the extras off, the JP pro is far less than the rest, but it seems like that's not a problem since the other options are in the same range. If you get MB, opt for the LE remake. It is the best MB ever made in my opinion (and for the majority of others). Is costs very little more, and it is newer...so the issues will be little to none.

If you opt for the JP, the premium is MUCH nicer, but it costs 2k more than the pro. You have to decide if the toys and art package are worth it. I think they are. Besides, if you are spending the much anyway...you should get what you want.

JP is deeper, but MB will be more kid friendly. Both have great lighting, sounds, themes, and rule sets. Both are family friendly. I don't think you could go wrong with either.

Attack from mars or Willy wonks would be 2 more you could consider with family, newness,
and quality considerations (but I think think both JP and MB are better, however).

No one can give you a definitive answer, but that's my 2 cents.

Both are very good games, but AIQ is the easy choice because it is far more family friendly, has easier shots (so newer and younger players will gravitate towards it more), and it will likely be easier to maintain in the future since it is a Stern.