6 and 1/2 week old kittens

Question
My boyfriend and I are adopting/rescuing four 6 and a half week old kittens. Given that they are so young what should we be doing for them?  The woman that rescued the litter has been feeding them dry adults' Iams and nothing else.  I bought them dry Iams kitten food last night and they are eating it without any problems.  Should I be giving them a mixture of wet and dry since they've only ever eaten dry food?  I've also bought some KMR the 2nd step for kittens that are 4-8 weeks.  Is this something that they should be eating since they are so tiny? I know any dietary changes will need to be added in gradually.  Is it even worth adding in wet food and the KMR at this point? They've been using their litter box and have had no accidents (knock on wood) so I don't think I need to worry about helping them expell food at this point.  Please correct me if I'm wrong on that thought.  They will be going to the vet next week to get their first round of shots and tests.  I'm just trying to make sure I keep them as healthy as possible until I get them there. Any other advice is appreciated. Thanks!

Answer
Actually, it seems like you have them on a great track and they are actually developing great cat skills ahead of time. Fantastic!

If they are using the cat box freely, continue to monitor each cat for bloating or fatigue, and if you do not notice either, it is safe to say they are all using the box and do not need your help excreting waste.

Iams is a good kitten food, I have always used Purina, but Iams is another great choice. Do not use Meow Mix, please. It tends to dehydrate young animals.

Keep the KMR in case one of them gets sick, but it doesn't look like they need it at this point. You may give some to the kittens as a supplement once a week, as well. Great vitamins!

I think they're doing fantastic. You're doing great!