Food for 6 wk old foster kittens

I have recently started fostering a litter of kittens 4 days ago and they were estimated to be 6 weeks old. They weighed in right at a pound each. They were wormed and are being treated with topical antibiotics for conjunctivitis in their eyes ( almost back to healthy/normal now)
Anyways, when I picked them up they gave me 2 ziplock bags of kitten food of an unknown (to me) brand so this is what they have been eating since I brought them home. I weighed them today and they have all gained slightly under 1 ounce. In my opinion, they should have been gaining more. They seem skinny but show no signs of illness.

I thought it might be the "unknown" dry food. So I started googling and figured out what the foods were - one was Grreat Choice from Petsmart (yuck) and the second was Purina Pro Plan (double yuck.)

I recently moved and live in a very rural area with little access to GOOD pet foods, so I always order online. But, I wanted to get these kittens started on something better ASAP so I searched locally and did find some EVO Turkey & Chicken formula for cats & kittens both dry and wet. I bought both and started the switch this afternoon and the kittens seem to love the EVO canned and did snack a little on the dry but I am concerned about the size of the pieces.....

Anyways. I can either keep them on this or order something better and use this until whatever I order gets here. If anyone has a better kitten food recommendation I would love to hear it. I don't want to do raw or anything too unknown/hard to find as these are fosters and in a few weeks they will be S/N and then adopted out. They were feral but not so much anymore I have not even heard a hiss in over 24 hours!

I see they seems to dont have difficulties with switching brand.  Yay!  Some cats have sensible tummy, and get upset at almost any change...  They of course dont grow up to adult semiferals....  

Anyway, the first word of caution isnt necessary, to change slowly and carefully...

The answer is easy. If they eat wet cat food, go for it.  Even mediocre cat food is at least as good as good dry cat food.  And good wet food... Probably no comparison.

The problem is some cats dont like wet food, for example, not my residents.  

The main reason for you to let them proceed on some dry food, is, you dont know what their furever adoption homes will fancy.  If they are hard on dry food, or happen in any emergency, it is good if they are used to eat also dry.

Go for wet.  And if you want to make little change, so, goat milk and all goat milk products are excellent. Plain youghurt works fine. You can melt in some butter in this plain, unsweetened youghurt.

Cheese is OK too...  Unsweetened youghurt with bifidus bacteria works as nice stabilisator, a basic probiotic. So good if they are used to it.

I myself dont know much about american brands, so let other recommend them.

Bozita, the swedish brand of wet food, is OK and one of the cheaper, I think.

Tx for helping them!

Good luck!