A big no on chewable vitamins. If you want to home cook, you really need a diet that is formulated by a vet nutritionist.
This is a website where you can get a free, balanced diet if you want to home cook. You do have to buy the supplements. The bottle is around $50 but lasts about three months.
www.balanceit.com
I personally would do as Taylor suggested.....stick with the YT kibble. My pups love it!
Once you start giving all sorts of different foods, they catch on quickly and will refuse food just to get another option. It's not a good thing to get into as it will lead to health issues in the future. Unbalanced diets are not good.