Growing Tomatoes!

Very cool! That's a lot of tomatos. Any plans for the payoff?
When plants get tall/thin like that they're called leggy. If you can, see if you can get them some more light. As another poster said, you can burry tomatoes pretty deep so even if you can't get more light it won't be the end of the world.
- Tomato sauce! Since they're San marzano tomatoes! As for light, there's no real good place to get them more light. The week before they go out in planning on putting them outside in the container to...harden them or something? If it fails, ah well, I will have learned!
  
  Tomato sauce! Since they’re San marzano tomatoes!
  I'm a bit jealous. I tried San Marzanos a few years ago and they didn't produce very well for me :(
  As for light, there’s no real good place to get them more light.
  Don't worry about that too much, just bury them deeper than they're currently planted and they'll be fine.
  The week before they go out in planning on putting them outside in the container to…harden them or something?
  Hardening gets your indoor seedlings used to three things:
  Direct sunlight. Even if you have grow lights at your disposal, direct sun is very bright. Your plants will get something equivalent to sunburn if you bring them into direct sunlight right off the bat and leave them there
  Changes in temperature. This is part of the reason why some will suggest bringing them indoors at night for their first few nights
  Wind, which can help encourage thicker stems
  Like cooking, hardening can be tailored to your plants/situation but when you're just starting off following a know recipe might be less frustrating. If your temperature is going to not be too crazy, and it's not going to be that windy, you can park your plants in a somewhat sunny spot for a week or so. Putting our seedlings under our kid's trampoline has worked really well in years past.

They look healthy and plentiful - I wish they were mine! Enjoy :)

Pro tip: If you pot these up into deeper containers and bury the stems as deep as you can you will have very hearty plants. If you continue growing the starts in these pots they will become root bound very "leggy" or tall and it will stunt future growth until they can recover.

What kind?
Pro-tip though, those started containers should probably be a 4" at minimum to get hearty tomato stems before transplanting. Those look to be about 1".
- I've used the 2" six slot trays to great effect all the time. All the tomatoes I've transplanted from those this year are doing awesome. Why would it need to be 4"?
  
  Ran a specialty growing operation for years, and there's a reason nurseries keep specific starter cell size for specific plants.
  I've done tests to see if we could increase yield by using smaller starter cells: 1", 2", 4", 6". The difference is drastic. When your cells are too shallow, you end up with what this picture shows here: height, but not much structural growth outward. With tomatoes the goal is get a certain amount of branching outward before it's healthy enough to transplant, and that's usually two branches top leaves, but the width of the stem is also important.
  If you start in cells that are too shallow, they get root bound and grow up, but not out much as seen here. If you give it enough space, you'll get both because the plant has extra room to expand: first outward, then upward. The large the root ball, the more energy can be expended upward for growth.
  So while you CAN use smaller cells, you'll always get the tall, thin types of starters as seen in this picture, not the same hearty growth you get from nursery plants. They may do fine, sure, but transplanting with a hearty plant means less time to adjust after planting before getting enough steam to really expand and branch out.
- Oh? Should I move them to bigger pots then? They're san marzano tomatoes!
  
  You can also plant tomato seedlings much deeper as they will grow roots from the stem. Plant them all the way down to their first true leaves. That’s what I’ve read at least.
  
  San Marzano, best. Well you shouldn't move them now as the root will be pretty fragile, but if you want starters that are as tall and hearty as a nursery would sell, you'll just need to start them in a bigger starter next year. It helps them to be more resilient to the initial shock of transplanting, and will make root ball damage less like as it will have more room to develop.