You all were so helpful when I started asking questions a few months ago

I'm back for Round 2!
Background: We've had 2 credit cards for decades (Discover and a Citi they changed from something else a year or so ago), but have decided to play the travel game

Ultimate goal is flying lay flat business to Australia and using points for some hotels there. I had hoped for 2019 but 2020 is more likely. We are DVC, travel to WDW as a couple once a year and as a family with our young adult kids every 12-18 months. Dh and I take a national parks-type trip once a year, generally flying SW. Youngest flies SW for school breaks. PHL and BWI are airports of choice.
Dh is a reluctant P2 who will
not apply for business cards. I have just finished homeschooling youngest and am contemplating getting back to tutoring like I did before we started homeschooling 8 years ago. So that would work as a legit business.
Me:
CF 7/18
(1/24)
DH:
CSP 7/18
(1/24)
I think going for the SW CP (so that it's valid for 2019-2020) is a good idea for us between our usual travel and visiting my extended family in CA more often. But when in relation to other cards? CIP is a good choice for me first because of the number of UR, right? CIC would be better in the long-run though, I think.
Double dipping kinda makes me nervous
Right now we can meet spends of $5-7K/3 months easily. $8-10K would take planning. We are considering some work on the house, though.
Suggestions with timing?
And another thing---I've read Chase prefers not more than 50% of income in credit limits. Is that combined across personal and business cards? And is there also a $ limit, rather than the 50% amount?
Thanks so much