Is all of this Enough for a first aid kit?

It seems like enough. People will start adding to your list but remember it's FIRST aid. You need to have the supplies on hand to treat something at first. You can always buy more supplies after the initial treatment, or depending on what your vet says. A few of the things in your kit will have expiration dates, so make note of them and replace the items when they have expired. You may also want to have some bute or banamine on hand, but you will have to ask your vet about that since they are available by prescription only.