Hello Evanmancini2011;
As you've read there are many ways to deal with a founding colony and if you practice good husbandry, Tetramorium immigrans should increase in size very quickly. My first impression of the two formicaria options was they look fairly small for this type of ants. Your first option, I think I looked at the right one, provides your colony with a nest, but no provision for feeding them. The colony at this stage really needs an area where you can safely feed them while they continue to use the test tube for their nest until it runs dry, goes grossly moldy, or becomes otherwise uninhabitable. Your second option provides both nest and feeding area, but ironically, I don't see any way to hydrate the nest and entice a colony to move there. The tubs and tubes system works well in the growth of a small colony, but I would like to suggest another alternative.
You could consider buying a little larger formicarium and use a short-term method to feed and tend your ants while they build up in numbers suitable for the larger space. I've had success just using a feeding chamber attached to the test tube, like the one pictured below.
Using a feeding chamber like this is going to allow a little more time when the colony can develop in the test tube while making the job of feeding and cleaning easier and safer from escapes. Hopefully your colony will quickly outgrow it and be large enough to move safely into something a little bigger that will also last them a little longer.
In this close-up you can see the feeding trays I use with protein on one and sponges with water and sugar/water on the other. I have a connection tube on the opposite side of the test tube that I eventually use to connect the colony to their larger formicarium. When they move out of the tube I can disconnect it, and continue using the feeding chamber attached to the new housing for a stress-free transition. This one also has a feeding port on the opposite side, so I don't have to remove the lid at feeding time. I've since moved the feeding port to the top which makes escapes almost impossible, especially with a coating of mineral oil on the rest of the inside of the lid.
This link will provide you with information on the feeding of protein to small ant colonies. Protein for new colonies - General Ant Keeping - Ants & Myrmecology Forum
You'll also find links there on the feeding and housing of small ants.
This solution will only provide a short time before fast growing ants like Tetramorium will require something bigger. I've used this system with slower growing ants like Camponotus and Lasius ants, sometimes it's all they've needed for an entire year. Good Luck with your colony.
RPT
My father always said I had ants in my pants.