Wow you've got a lot of tanks, but that is great news. If something goes really wrong you can just plop one species in a 10 gal for a bit.
Orange and black? That does sound like a platy. Take a look at the pictures in our profiles and see if you can make a match. The good news is, they can live with the white clouds. Platies and a lot of livebearers actually come from cooler than average tropical temp waters.
More good news is that a lot of the small tetra can live together. The neons, cardinals, glowlights, corydoras, and black neons all come from similar waters. Provided each species has a school of 6 or more, you'll be set. You could throw these schools in the 55 gallon and plant it. AqAdvisor stocking for 55 gal
I am hesitant to suggest this to beginner aquarist because most see it as a be-all-end-all kinda thing. As long as you take it as a guideline, it can be a great tool.
Move the platies and minnows to the 40 gallon (you'll want to keep the temp between 70F and 74F). You can actually keep the black veil tetra in there, too; they could also be with the other tetra in the 55 gal, but that might make the aquarium look a little crowded. AqAdvisor stocking for 40 gal
This leaves open one 29 gal for the serpae tetra and a bottom-dwelling fish like bristlenose pleco or more corydoras if you feel like it. The other 29 gallon can be used for your kribs when/if you get them. And you still have the 35 gal corner tank if you decide you want to remove one or two species from the 55 gal (if you think it looks too crowded). The betta will be fine where they are. How is this sounding?
Have you ever had to stuff a bunch of boxes and bags in a car to move? My friends and I call that tetris packing (did it a lot moving too and from college). This is kinda like tetris stocking!